Life Knife
From Tardis Wiki, the free Doctor Who reference
The Life Knife was a three-bladed knife (8 Inches deep by 3 inches wide) used by Suzie Costello to kill people in order to test the Resurrection gauntlet. (TW: Everything Changes) After Suzie's death, the knife was locked away in Jack's safe sealed with a "NOT FOR USE" tag. The knife was associated with the glove as they were made of the same metal, and those killed with the knife were easier for the Glove to resurrect.
Stabbing the deceased with the knife could increase the connection with the glove even post mortem. The name "life knife" was coined by Ianto Jones. (TW: They Keep Killing Suzie)
