Who is Quinn in 'The Boys' Season 5? New character sparks major theories

The latest episode of The Boys Season 5 introduces a mysterious new figure, Quinn, who may hold the key to Soldier Boy’s past.

Appearing in Episode 4, Quinn is discovered inside a lab at Fort Harmony, a twisted testing ground tied to early Compound V experiments. Played by Kris Hagen, the character is found barely alive, pleading for death after being exposed to a rage-inducing toxin.

The situation escalates when Soldier Boy, portrayed by Jensen Ackles, accidentally kills Quinn during a confrontation, a moment that unexpectedly reveals a more emotional side to the otherwise brutal supe.

But Quinn’s true identity remains unclear, and that’s where fan theories take over.

One of the most popular speculations is that Quinn could be Soldier Boy’s brother. The episode hints at Soldier Boy’s privileged past and mentions a sibling who was a decorated soldier, making it plausible that Quinn was involved in early Vought experiments while Soldier Boy forced his way in.

However, this theory isn’t airtight. The show has previously stated that only a handful of individuals survived the original V1 trials, and Quinn is not among those confirmed names.

This raises the possibility that he may have been experimented on later, or removed from the official record altogether.

Another interpretation is more straightforward: Quinn may not be related to Soldier Boy at all, but instead represents someone he once cared about deeply. His death, and Soldier Boy’s visible grief afterward, suggests a rare moment of humanity for the character, especially in front of Homelander, played by Antony Starr.

Whether Quinn is family, a former ally, or simply a symbol of Soldier Boy’s past, the character clearly carries emotional weight, and his brief appearance is already shaping fan discussions.

With more backstory expected in the upcoming prequel series, the mystery of Quinn may not stay unsolved for long.