Fidelma is thrown when James reveals he can give her the name of the Rafferty development arsonist in Sunday's Fair City on RTÉ One and the RTÉ Player.
"Make me a source and I'll give you a name right now," he says.
The blaze was set by Anto, the father of James's estranged wife Hayley, in a bid to solve Hayley's financial problems.
Fans can watch what happens next on Sunday on RTÉ One and the RTÉ Player at 8:30pm.
Fair City airs on RTÉ One and the RTÉ Player on Sundays, Tuesdays, Thursdays, and Fridays.
