Life Knife

The Life Knife is a three-bladed knife used by Suzie Costello to kill people in oder to to test the Resurrection Gauntlet in "Everything Changes". After Suzie's death, the knife was locked away in Jack's safe sealed with a "NOT FOR USE" tag. The knife is associated with the glove as they are made of the same metal, and that those killed with the knife are easier for the Glove to resurrect.

Stabbing the deceased with the knife can increase the connection with the glove even post mortem. The name "life knife" was coined by Ianto Jones.

Flashbacks in Everything Changes" shows Gwen Cooper remembering seeing Suzie either constructing or repairing the knife upon her first visit to the Hub. This was how Suzie was discovered as the killer in the first episode.

Notable Quotes

Owen Harper: (as Jack gets the knife that joins with the Glove) "Ianto?" Ianto Jones: "Life knife."

Captain Jack Harkness: (after Jack shoots Max with a stun-gun) "That one's for Ianto. Risen-Mitten, Life Knife, and the all time favourite, the Stun-Gun."