When the hot water boiler in the Halls breaks, Jessica Harris (Jennifer Biddall) offers Danny £50 to fix the boiler. Despite telling her he has little experience fixing boilers, Danny agrees to help. While examining the box, he notices a hole which is causing the pilot light to go out. While Jessica's back is turned, Danny blocks up the hole with newspaper. Unfortunately, this causes a buildup of carbon monoxide. Later, at a house warming party for John Paul and Kris Fisher (Gerard McCarthy), the gas causes everyone to feel ill. Danny leaves with Mercedes before the others begin to lose consciousness. Danny and Mercedes go to the SU Bar and kiss, and were interrupted by a phonecall from Justin, saying that the party guests are unconscious. They rush back to the party and Danny helps Justin save the guests. Danny refuses a lift from Darren Osborne (Ashley Taylor Dawson), who suggests he ought to go to hospital to be checked, but Danny flees. Jessica visits him the following day, suggesting that the two of them keep a low profile. However, Danny cannot handle the guilt and confesses the truth to Mercedes. Jacqui McQueen (Claire Cooper) overhears, threatening to beat Danny up, but Mercedes protects him. Later, Jacqui and Myra McQueen (Nicole Barber-Lane) force Danny into confessing that Jessica was the one who allowed him to fix the boiler. Myra and Jacqui then threaten to sue Jessica. A few days later, Myra takes some money Jessica was given by Zoe Carpenter (Zoë Lister), resulting in the McQueens forgetting the incident.