Derek Peterson

Lieutenant Commander Derek Peterson is the main protagonist of Australia S-Unit, and is portrayed by Daniel Isaac. The character was created by Daniel Isaac and James Burnell. For the first and second seasons of the show, Derek is partnered with Marcus Andrews.

Early years (2003-09)
Derek worked with his partner, Kale Anderson, for S-Unit from 2003 to 2009. He and his partner worked on many cases and solved them together. Early 2008, Derek and Kale started a man hunt for Caesar Solomos, a drug lord in Queensland who S-Unit had been hunting for years. In 2009, Derek and Kale tracked down Caesar to an apartment complex in Brisbane. Derek, much to Kale's complaints, bursts into the complex to arrest Caesar. However, Kale was caught in the crossfire and took a bullet from Caesar and subsequently died. Derek was in shock over Kale's death but tried to hide it for reputations sake.

In 2010, Derek was assigned to Marcus Andrews, who went through his own losses too. Derek worked with Marcus on several unnamed cases and eventually worked on a case where several victims were killed from drug overdose.

Hunting Mr Greene (2011-12)
In 2011, Derek found a lead on the drug case and, with Marcus, he entered a reported drug house. Finding nothing there, they also found a screen displaying Derek's house blowing up. Determined he was onto something, Derek moved into Marcus' house to work on the case. After some hours working on the case, Derek and Marcus went to lunch where they encountered a man who opened fire at them. After pursuing the suspect back to Marcus' house, Derek arrested him and questioned him, learning of his employer named Lucas Greene. The illusive Mr Greene had planned for Derek's house to be destroyed, claiming that Derek was getting to close to something big. Mr Greene rang Derek and told him to back off. The suspect was also shot from the distance by an unknown shooter. Determined to arrest Mr Greene, Derek headed to Sydney to talk to one of Greene's previous employers, Allan Faraday. Derek learnt from Allan that Greene was a big time drug lord and imported drugs into the country through major planting foundations. After receiving an address, Derek went back to Brisbane to find Greene. Derek and Marcus headed to the address and encountered Greene. They arrested Greene, however claiming later and learning that the man they arrested was not actually Mr Greene, but rather a decoy.

Derek then worked with Marcus on several other cases. Six months after the first encounter with Mr Greene, Derek worked on a case involving the man who killed Cynthia, Marcus' girlfriend. Derek helped Marcus to come to terms with her death and arrested Roman. Derek also learnt from Greene's decoy, Jackson Grant, that Greene will reveal himself to Derek when he wants to. Derek also claimed to Marcus that maybe Roman wasn't actually Cynthia's killer, and that the real killer may in fact still be out in the world.

Another case Derek worked on with Marcus was the kidnapping of Cassandra Blake. Derek and Marcus found the kidnapper, however at great cost Marcus was shot and supposedly killed. Derek then encountered the true Mr Greene for the first time outside the kidnapper's location. Mr Greene revealed himself and claimed that Derek's life was going down hill from now on. Derek attempted to pursue Greene but was hit to the ground.

Without Marcus (2012)
Derek, after Marcus' supposed death, spent three months in depression. He was saddened over his friend's death and rarely worked on any cases. Brad Fisher was assigned to help Derek get back on his feet and help him track down Mr Greene. Investigating several murders, Derek and Brad were attacked by a man sent by Greene. Derek was however saved by Marcus, who in fact survived. Marcus told Derek where Greene was and that he was put into witness protection and had a secret assignment to infiltrate Greene's business. Derek and Marcus then headed to find Greene and arrest him.

Confronting Greene
Upon finding Lucas Greene, Derek arrested him, but quickly learnt that he had men set up C4 to detonate in the city if he wasn't released within the next few hours. Determined to save the city, Derek tried to find the bombs, finding only two but was eventually forced to give in and release Greene. Upon releasing Greene, the bombs were detonated regardless and Derek pursued Greene. What started in a rigged car chase ended with Derek chasing Greene in the streets. Greene aimed his weapon at Derek and was about to shoot when another shot was fired. Derek was saved by Marcus who killed Greene. Greene, finally dead, however left a lot of sins for the city to clean up.

Six months later, Derek and Marcus continued to investigate cases.

Greene's Rival (2013)
In early 2013, Derek and Marcus, now in a new house, investigated a number of murders on suspects who worked for the deceased Mr Greene. Derek discovered that Greene had a rival in the crime business, named Ryder Dixon. Derek discovered from Allan Faraday that Ryder was the one who started the whole crime war between Greene and Derek, giving Derek a location to go to to find Greene, which was the house where Derek and Marcus saw Derek's house blow up. Derek told Marcus and the two were confronted by Ryder Dixon himself soon after. Derek shot Ryder, wounding him and saving Marcus. Ryder was taken to prison for his crimes. Soon after Derek received a phone call from Allan Faraday that a victim murdered in the Solomos Case in still alive.

The Hunt for Cynthia
Derek learnt that Cynthia Solomos was alive and failed to inform Marcus. Derek eventually learnt that Marcus knew she was alive as well and decided to help him find her. The two encountered Roman Duke again who escaped prison after informing them about Cynthia and Greene's second in command. Derek and Marcus pursued Roman to one of Greene's old facilities. There Marcus killed Roman and Derek witnessed his friend's redemption.

Marcus was eventually kidnapped by the man who was haunting Marcus. Derek, not knowing where to look, got in contact with Brad again to help him find Marcus. Eventually Derek found Brad, but at a cost, was wounded and discovered that it wasn't Cynthia who was alive, but in fact Derek's old partner, Kale, who was believed to be killed in action.

Outlaws
In May 2013, Derek and Marcus were framed for the assassination of the Prime Minister. The two went on the run from the authorities for an entire week. The two tried to seek refuge with Brad but they could not stay. A week later Derek and Marcus decided to take down Kale to end the game. Derek and Marcus confronted Kale and Marcus murdered him. Derek, determined to still prove their innocence, asked Marcus to take Kale's phone. Marcus was then killed by a specialists team outside. Derek, who was distraught over his friends death, tried to fight off the Unit, but was arrested and taken to Brisbane State Prison to await trial, much to the shock of some of his friends.

Prison Days
Shortly after Marcus' death, Derek was arrested by the police and taken to court where he was found guilty of murdering the prime minister and Kale Anderson. Derek was placed in Brisbane State Prison serving a life sentence. Due to his failure to help Marcus, he believed he deserved to be in prison. Derek was locked up for six weeks until eventually Brad Fisher visited him and informed him that he along with the commissioner of S-Unit were invesitgating a possible link to Mr Greene named Henry Jacobs. Believing Jacobs to be Greene's Queensland Representitive for his crime organisation, Brad tried to convince Derek to help him. Derek declined and remained in prison. The next day Brad returned and told Derek that he found out Henry is also partly responsible for Marcus' death. Derek is then taken outside while the officers inspect his cell. Outside he confronts Ryder Dixon, who is also imprisoned with Derek. The two fight until they are broke apart by the prison guards.

Due to his attitude in prison and for having such bad relations with inmates, Derek is transfered to another prison, however on the way Derek knocks out his two guards in the car and escapes.

Personality
Derek is a strong willed character who will do anything and everything he can for friends. Derek isn't easy to make fearful or sad. An example of this is with the death of his partner, Kale. He didn't take Kale's death lightly but he also did not let his death ruin his life. The same cannot be said with Marcus' death however as Derek shows clear signs of emotion as he loses his best friend. Derek is noble and never gives up, strictly breaking the code of conduct to get things done. Derek has a strong idealistic crusade for Lucas Greene as he will stop at nothing to end his business. Derek is also portrayed as being caring but rarely showing it. He is also a very stubborn character as he only ever believes his words are right and excludes all others reasons.

Marcus Andrews
Derek became partners with Marcus in 2010 where the two quickly became friends. The two worked on many cases together but it wasn't until 2011 when they started working on the Greene case that they grew closer together. It wasn't until 2012 however when Derek finally learned about Marcus' dreadful past, including his drug addiction and the death of his girlfriend, Cynthia. Marcus' supposed death in 2012 lead Derek to a larger hatred of Lucas Greene. When Marcus returned, Derek's friendship with him increased in value and they became best friends. In 2013, Derek wanted to help Marcus find Cynthia as he wanted his friend to be happy again, knowing he is still in withdrawal. Upon Marcus' death, Derek didn't take it lightly, in fact he opened fire on an S-Unit raid team in anger and hatred for his death. Derek's relationship with Marcus was also filled with arguments and laughs. The two often had many arguments on the lead up to Marcus' supposed death, however after his return, the amount of arguments decreased greatly.

Brad Fisher
Derek's relationship with Brad has not been explored entirely as the two have only been on screen together several times. Derek considers Brad a great friend, having met him through Marcus. Derek and Brad never argue compared to Derek and Marcus' relationship. Brad often helps Derek with cases when Marcus cannot. Derek considers Brad to be the only other person he can truly trust and this is evident when he suggests to Marcus that they visit Brad when they were on the run from the country.

Lucas Greene
Derek, upon learning of Mr Greene, grew a desire to find and arrest him. When Marcus was shot by Jonathan Blake and supposedly killed, Derek's anger for Mr Greene grew frantically and he swore he would find and kill Lucas. Derek searched for Mr Greene for three whole months leading up to his long awaited arrest. Upon Greene's death, Derek immediately felt relieved as the sins that weighed on his shoulders finally released.

Kale Anderson
Kale was Derek's partner in S-Unit from 2003-2009. He was friends with Kale, although not as much friends as Derek was with Marcus. Kale and Derek worked together on many cases over the years leading up to the raid on Caesar Solomos' apartment, where Derek got Kale killed. This was however Kale's plan as Kale was working for Mr Greene the entire time and set up his fake death to leave S-Unit and continue working for his best friend Lucas Greene fulltime rather than a spy for him. Kale's reveal that he was still alive shocked Derek to the core and ultimately made him fearful of what Kale could do.

Allan Faraday
Derek's relationship with Allan is one of friendship and one of enemies. Derek knows Allan worked for Mr Greene however Derek, after visiting him twice on screen and several times off screen, eventually considered him a friend.

Trivia

 * Daniel Isaac confirmed that the character of Derek Peterson was inspired by Steve McGarrett from Hawaii Five-0.
 * Derek was created to be the hero of the story with no emotional breaks compared to that of Marcus.
 * Derek has worked for S-Unit since 2002.
 * It is hinted that Derek has or had a romantic status with Carol Stewart, Marcus' step sister.
 * Derek met Marcus in 2010.
 * Derek was partners with Kale Anderson from 2003 to 2009, before his supposed death.