Guest Stars Dominic MacHale as Sergeant Healy Demi Isaac Oviawe as Linda Walsh Jennifer Barry as Siobhan Walsh P.J. Gallagher as Principal Barry Walsh Orla Fitzgerald as Orla Walsh Pat O'Connell as Mairead's Boss Sean O'Connell as Fishmonger Con O'Connor as Customer at Fish Counter Martin McDonagh as Teen Chasing Fish Dylan Corcoran as Teen Chasing Fish John Corcoran as Teen Chasing Fish Kellie O'Gorman as Teen Chasing Fish Katie Walsh as Teen Chasing Fish Conor Dwane as News Reporter Martin Walley as Customer at Fish Counter Paul O'Connell as Fishmonger Emma O'Connell as Fishmonger Colin Murphy as Customer at Fish Counter