J.J. Macfield is the titular protagonist of 2018's The Missing: J.J. Macfield and the Island of Memories. After finding herself on Memoria Island, J.J.'s best friend and suggested love interest, Emily Thompson, begins acting strangely and runs away, forcing J.J. to chase after her. J.J. quickly discovers that she can regenerate her body from almost any injury, a trait which is necessary for her to continue chasing Emily.
At various points along the island, J.J. is chased by the Hairshrieker, a large monster with flowing, gray hair and a box cutter. Whereas most of the dangers J.J. faces on the island are environmental hazards, the Hairshrieker is one of the few living beings on the island actively trying to harm her.
Throughout the game, players unlock past texts between J.J. and her associates, filling in the gaps in J.J.'s past. J.J. is a seemingly-model college student with an interest in design and a penchant for sweets (especially donuts.) However, J.J. often overworks herself, is somewhat reserved in her social life, and hides a secret known only to herself and Emily, who J.J. is much more open towards.
While it is initially implied that J.J.'s secret is a lesbian relationship with Emily, her secret is later all-but-explicitly stated to be that she is a trans woman. This is suggested by J.J. being on the receiving end of harassment after a classmate finds her renting a book about an unspecified condition, and by J.J.'s mom taking her to a conversion therapist after she finds womens' clothing in J.J.'s dresser. Concurrently on Memoria Island, J.J. reaches Emily only to find that she has hanged herself, leaving behind a suicide note signed "Sorry mom, sorry Emily." As a result, J.J. briefly turns into the Hairshrieker before remembering that she attempted suicide before waking on Memoria Island, suggesting she's now dreaming before she dies.
Despite this, F.K. encourages J.J. to continue living, prompting her to fight the Hairshrieker. Upon the Hairshrieker's death, J.J. wakes up in the real world to an EMT resuscitating her. In the real world, J.J. has short, dark hair and a slightly deeper voice. This model is then unlocked for the player to use in subsequent playthroughs, complete with re-dubbed voice acting for J.J.'s lines.
- J.J.'s dream design bears a notable resemblance to certain depictions of Alice from Alice in Wonderland.
- J.J's connection to clock towers is potentially an allusion to Thomas, a character from one of Swery's previous directorial works, who harbors a somewhat similar secret and dies at a clock tower.
- How characters refer to J.J. often suggests their relationship, with J.J.'s close friends referring to her as J.J., while her mom and Lily, the two characters who antagonize her for her secret, only refer to J.J. by her full first name.