Claire Redfield's search for her brother lands her on Rockfort Island in Resident Evil Code: Veronica. Capcom's 2000 Dreamcast game is a mainline entry even though it sits outside the numbered titles, with Alfred and Alexia Ashford as the island's keepers.
Fixed cameras, a limited inventory, and a second half that finally brings Chris in are the survival-horror grammar. Antarctica and the Ashford family plot push the story past Raccoon City without turning it into a spinoff.
Numbered sequels kept Leon or a new outbreak. Veronica is still canon, the chapter where Claire is the prisoner and the Ashfords are the reason.