Will Henderson is the son of Mary Henderson.
Will was captured by a soul eater on his family's first night at a new house. While his body was left in a comatose state, his soul was trapped inside the monster's nest along with a few other trapped souls.
Hunters Bobby Singer and Rufus Turner sought to free Will once they found out what they were dealing with. Bobby used a Celtic Monster Trapping Sigil, but was dragged over to the nest before he could finish the task.
Will encountered Bobby upon the latter's arrival. Bobby promised to help Will escape, following which Will encountered his mother in the Nest, while the Soul Eater pounced on Bobby and possessed him in the real world.
After much difficulty with fending off the possessed Bobby, Rufus completed the sigil in Bobby's stead, thus trapping the Soul Eater and all souls within the Nest. Given the nature of the Nest being outside time and space, Sam's use of the Men of Letters Killing Sigil, managed to kill the Soul Eater in 2017 and subsequently destroyed its Nest. Freeing all souls that were trapped inside the nest, back to their respective time.
After the incident, Will and his parents moved out from the house. It was purchased, years later, by Naoki Himura.