After arriving in Erinsborough, Mark assumes the identity of Marcel Amadieu and poses as a French chef to get a job at Lassister's Hotel. Annalise Hartman soon uncovers the ruse and Mark asks her to keep quiet, explaining that he has come to reconcile with his brother Stephen. Mark spiked Stephen's drink during a party, leaving him unable to drive his fiancée, Libby, home. Libby took a taxi, which crashed and killed her. Stephen blames Mark for the accident. When Mark visits Stephen at his home in Ramsay Street, he is shocked to find him in a wheelchair following an explosion at the local pub. Stephen suffers a relapse triggered by Mark's arrival. Mark wants to make amends, but Stephen's wife, Phoebe (Simone Robertson) and friend Wayne Duncan (Jonathon Sammy-Lee) want him to stay away from Stephen. Mark perseveres and eventually Stephen forgives him.