Ewan is one of the ten prisoners on death row bought by the billionaire Ian Breckel to participate in his reality death fight show. However, he is the only one who has an additional agreement with Breckel. McStarley agreed to put on a 'good show' and in return Breckel would give him the necessary backup so he could win.
Prior to his involvement with Breckel, Ewan McStarley was in Ruanda, possibly during a SAS black-op, and burned down a village, where he killed and tortured 17 men and raped 9 women. 'All in a day's work', as Ewan commented. He got sentenced to death and according to a later statement was raped twice a day while being kept in prison waiting.
Even before the convicts are thrown out onto the island, he begins making remarks that he had an interest in Rosa, the female part of the Mexican killer couple. However, his first deed on the island is to form an alliance with Saiga, the Japanese death row candidate. At this point McStarley is already armed with a small knife, it's not clear whether he had it from the beginning or whether it was in the "Christmas package" Kreston got earlier.
Eleven hours into the game McStarley comes across the recently re-united Paco and Rosa. An attempt to protect his wife fails miserably when Paco tells her to run away while attacking McStarley. Ewan's partner Saiga stopped Rosa from getting away and her screams distract Paco, giving McStarley the chance to grab a branch which he uses to break Paco's knee. But instead of killing him he uses Paco's weapon of choice, the chain in which he arrived on the island, and strings him up against one of the trees, forcing him to watch what he does to Rosa. McStarley teases her and after she hits him with her fist goes berserk and starts kicking and beating her. He and Saiga are obviously so caught up in this that they don't even notice the live camera team approaching and filming as they McStarley apparantly goes on to cutting her with his knife and probably also raping her. Which is however not shown, but from his record and other comments made insinuated. Afterwards Rosa's leg bomb goes off, it is not clear whether she pulled it herself or if that was McStarkley's doing.
Just as Ewan was going to gloat he notices that Paco had freed himself and limbed away. Both of them start to pursue him. Here Breckel provides assistance him by sending a second package for McStarley handing him and thus also Saiga more tools: two big knifes, a compact bow with some arrows, three Molotov cocktails, a big machete and something to drink and smoke. It is also implied that he got information on the location of Paco, as Breckel said that they should send McStarley to the Japanese ruins.
At the ruins the two find the helpless Paco and begin to brutally torture him kicking and hitting him at especially vulnerable spots. After Jack Conrad showed up on the other site of the river, McStarley engage in a rather revealing dialogue. Somewhere through it Ewan shots an arrow at close distance into Paco's chest. Not long afterwards, Saiga pours the content of the Molotov Cocktail over Paco and using the ciagrette he was smoking to set him on fire whilst still being alive. Ewan also used this scene to ensure that Conrad would come after them.
The next day McStarley and Saiga wait for Conrad by the Japanese ruins, Saiga gets attacked first. Hearing how his partner gets beat up, causes Ewan only to grin, before he jumps down with the bow ready in hand. He shots at Conrad who is about to choke Saiga. However Conrad escapes and McStarley pursues yelling at Saiga to get up. They trap him at a bunker filled with old military equipment. Saiga uses the last two Molotov cocktails to set the building on fire while McStarley shots an arrow into the bunker. Only that instead of hitting Conrad the arrow lands in Yasantwa's back. The black woman then choses to pull her strip and detonate the bomb. It gives Conrad time to escape, but not knowing that he surved McStarley and Saiga now face each other. Saiga realises that he has to run as Ewan is still armed with one more arrow. McStarley sets after him and aims at his back, but misses. Dropping the bow Ewan grabs the big machete given to him by Breckel. Catching up with Saiga Ewan finds Conrad alive and fights again with Saiga. He even nods at Saiga to go first at one point, but quickly finds himself alone.
With the odds not in his favour McStarley favours running till both face each other again on top of rocky cropping just above a canyon. There Ewan jumps down next to a waterfall. All this gives Breckel enough time to sent him another Christmas package, this time with a shotgun. Conrad who jumped after McStarley is nearly shot but escapes back into the water. Which gives Ewan time to notice the live unit, two camoflaged men: one with a camera, the other with a MAG-5. One is shot as the tries to raise his automatic rifle, the other has time to identify him. Ewan just say: 'Film this'. Then shots the camera man. Now armed with more fire-power McStarley continues to look for Conrad.
Conrad surprises him from behind and manages to disarm him. Both begin to kick and beat each other, before Conrad gains the upper hand. However, McStarley manages to grab a small knife, possibly the same he already had from the very beginning, and cuts Conrad with it. Without much ado he kicks his opponent away, lungs for the shotgun and fires two shots in his direction. Conrad slides down the slippery rocks and ends up floating face down in the body of water and Breckel declares Ewan as the winner of the game.
Two armed men are later seen bringing Ewan to the base camp, where McStarley first demands to his leg bomb removed. As soon as Breckel tells him that he does not intend to honour their agreement by withholding the money, Ewan is really pissed. He cons a smoke from one of the guards and as the man leans in to light it, he punches him in the face and grabs his knife slashing his throat. The other guard then gets stabbed with the knife, before the previous guard hits the ground McStarley also stabs him once more.
Taking one of the fire-arms, Ewan walks into the command centre and confronts the computer personnel who previously had cheered and enjoyed McStarley's doings. Now all of them, save Breckel's ex girlfriend Julie, are close to panicking and are shot one after another by Ewan starting with Bella and stopping with Eddie. Before McStarley has a chance to harm Julie, Conrad shows up in the tent with a gun pointing at him. As McStarley notices him, he lowers his weapon and drops it to the floor. Turning around he talks to Conrad obviously in an attempt to bond with him by sharing his life's story, but Conrad is not impressed and simply shots Ewan McStarley seven times.