Alice ends up risking everything to discover the truth behind her brother’s disappearance. Quentin and Julia are involved in a volatile reunion.

Malcolm puts Oliver and Thea in a dangerous situation that lands them on Lian Yu with Oliver’s former enemy Deathstroke. In a flashback, Oliver and Maseo return to Starling City…

Shawn and Gus investigate a department store Santa who they suspect is up to no good. Meanwhile, Gus’ sister flies in for Christmas.