"I'll come back for you". You may remember this line from the Sole Survivor's escape from Vault 111. What you probably don't remember is what you were coming back for--the Cryolator. This unique weapon, featured frequently in Fallout 4 loading screens, is a product of Vault 111's cryogenic research, and can be yours once you reach a certain level in the Locksmith perk.
Upon revisiting Vault 111, you can enter the facility by first switching a button in a nearby shack to trigger the elevator, then standing in the center of the entrance. Once you reach the bottom, the chamber where you were frozen is straight to the back, if you wish to revisit your frozen spouse. In the nearby Overseer's office is the locked box containing the Cryolator, behind a Master lock. You can learn more about the weapon at the Overseer's terminal.
The Cryolator goes through ammunition very quickly, however, it is useful in that it sometimes can freeze an enemy solid. It can also be modified like other weapons.
Did you konw The Cryolater is also a weapon that was cut from the original Fallout 3? The more you know.