Damien makes a shock request in Christmas Day's Fair City on RTÉ One and the RTÉ Player.
Earlier this year, Tyler was released without charge after he was questioned about the murder of Damien's sister Laura.
Damien subsequently kidnapped Tyler, but Tyler escaped.
Since then, Damien has been receiving treatment for a nervous breakdown.
In the Christmas Day episode, Damien and Tyler cross paths in Carrigstown.
"I'd like you to do something for me," says Damien.
"Interesting," Tyler smiles. "What can I do for you?"
"Forgive me," replies Damien.
Fans can find out what happens next on Christmas Day on RTÉ One and the RTÉ Player at 8:10pm.
