The Virgo Blade is a weapon that curses the victim and causes rose vines to grow from the wounds until they reach and strangle the heart of the victim.
The blade was used in The Strangled Heart by Mike McCormick in an attempt to kill Quentin, but was thwarted by Penny, who jumped in front of Quentin and was subsequently stabbed by Mike in the process. The curse was eventually lifted by sacrificing a wrapper from a chocolate bar that Kady had given Penny at Brakebills South.
Before being used by Mike, The blade made an appearance in the 5th Fillory book The Wandering Dune, where a Lorian assassin attacks Jane Chatwin. With the help of Honeyclaw, a talking bear, Jane was able to remove the curse by offering a doll her mother had given her as a sacrifice in place of her heart.
The blade, upon cutting, curses the wound, from which vines slowly grow out of, until they reach the heart of the victim, and strangles it to kill them.
It is possible to remove the curse by sacrificially burning the item that is the "most precious possession" to the victim.
- When first attempting to treat Penny, they burn a voodoo doll of him that Quentin sews together.