Excalibur #25 (1990) Page 22: Courtney takes Kitty for a ride

Excalibur started as Chris Claremont's opportunity to write something goofier than the highly melodramatic X-Men. Issue #24 ended founding artist Alan Davis' first run, and #25 was Claremont's last issue for a while as well. He had concluded the multiversal "Cross-Time Caper" with Kitty Pryde separated from the team, being groomed by the sinister Courtney Ross.

This page shows Courtney discussing Kitty's enrollment at a girls' school in England. Kitty (age 15 by now) disappears from the series for six months, returning when Claremont himself does for the "Girls School from Heck" arc in #32-34, which starts as "Heathers" and ends as "Bring It On." This is the second time that a blonde antagonist forced Kitty to attend boarding school, by the way.