In The Watcher in the Woods (1980) second 1981 theatrical release with reshot ending, we get to the film’s climax.
Jan Curtis hatches the plan to recreate the original ceremony during the upcoming solar eclipse, hoping it will bring Karen Aylwood back.
During this ritual the Watcher now as a pillar of light was in process of lifting Jan into air when Mike intercedes and pulls her away before the Watcher disappears. Simultaneously, the eclipse ends, and Karen, still the same age as when she disappeared, reappears – still blindfolded.
It’s a relatively closed, happy ending. Karen is returned (albeit not having aged a day during her absence), and Jan is alright.
Do we know what was otherwise supposed to occur if Mike hadn’t jumped in to molest the Watcher’s activity? Again, I’m mainly just interested in the 1981 final theatrical version, but any insight as to what the Watcher had intended to do is welcome.