Pickman's Blade

Pickman's Blade is a unique combat knife found in Fallout 4. It is obtained in Pickman Gallery as a reward for the quest Pickman's Gift.

Characteristics
On a hit, targets bleed for an additional 25 points of damage. It also comes pre-equipped with the Stealth Blade upgrade and therefore deals additional sneak attack damage multiplier of 0.6.

Pickman himself may sometimes appear, to watch your handiwork.

Location
The weapon is located inside a wall safe, behind Pickman's painting "Picnic for Stanley". In order to get the key, you must work your way into the lowest room of the gallery, and rescue Pickman from a group of raiders. Afterwards, when talking to him, he will express his gratitude and give you his key. Alternatively one may let the raiders kill Pickman then loot the key off him later, however, this will not prompt the player to go to the painting.

In order to find the painting he is talking about, return to the front door, then immediately enter the room on the left side of the hall. It will be a picture of a man's face; when the reticle is placed on it, you will receive a prompt to take it off the wall. This will reveal the wall safe, and within lies your prize, along with some caps and a thank-you note.

Behind the scenes
The knife is a possible reference to H.P. Lovecraft's short story, "Pickman's Model" as the main character of the story is Richard Pickman, a painter.