Fathers' Day by Ursula

Father's Day
Krycek discovers a child born in a lab that has ties to him and Mulder both. m/m slash BF W

Father's Day II
sequel to Father's Day. Mulder, Krycek, and their baby son Jacob learn to be a family. m/m slash BF W

Folie
sequel to Father's Day II. Krycek arrives with an imaginary babe in arms that he believes is his and Mulder's.

Vows
Continuation of the Fathers' Day series. NCC BF