"The Invisible Hand" (No. 63), a group of six childhood friends from a town poisoned by chemical toxins. They kidnap corporate and political figures responsible for the environmental disaster to bury them alive in the contaminated soil.

Liz continues her investigation into Tom's death and discovers that the mysterious "Oleander" is actually her grandfather, Dominic Wilkinson.

Critics noted the episode successfully brought Liz back to the Task Force but struggled to balance its three competing plotlines. The Invisible Hand (Podcast)

[Spoilers] Post Episode Discussion S5E13 "The Invisible Hand"