After his father, Edgar, was killed in military custody on April 3, 2076, Martin and Olivia were put up by the Navy for adoption and were, according to official records, placed in new families within two months. However, in reality, Martin was used as a child test subject for the Navy's Somnus Initiative. With a history of attempting to flee custody from his orphanage, Martin was the best candidate for testing the effects of brainwashing a child subject. The Somnus Initiative brainwashing worked too well on Martin, as he became nothing more than a living robot that would only follow direct orders and do nothing to maintain his health, such as eating, sleeping, bathing or even using the toilet. The scientists for the Somnus Initiative noted that the brainwashing should only be used on adults from then on, and accelerated the deprogramming phase for Martin after learning of its adverse effects on children.
Martin Aarsen is mentioned only in Fallout 76.