Clue, the basset hound, disappears from the cabin, and it is up to the girls to find her.

Ashley and I were on a ski vacation, and we couldn't wait to hit the slopes -- until we heard the scary legend of Ski Mountain. According to the story, a monster snatched a boy right off the ski slopes! The boy was never seen again. But it was just a story. Or that's what we thought. Until our ski lift stopped mysterious in midair... And the tree outside our cabin was ripped apart... And we found giant footprints in the snow. We were on the case. Was there really a Ski Mountain monster? We were about to find out -- one way or another!

Mary-Kate and Ashley must find a missing robot before the science fair is cancelled.

Mysterious happenings at Camp Crooked Lake have the twins solving another mystery.

Mary-Kate and Ashley are excited to attend their town's annual Halloween Carnival. Every year, the carnival's proceeds go to charity -- but this year, few people are riding the rides or playing the games. That's because there's a ghost at the carnival that's scaring all the kids away! The girls must figure out who or what the spectre is -- and how to get rid of it -- or the carnival doesn’t stand a ghost of a chance!

Mary-Kate could be kicked out of the upcoming horse show if the Trenchcoat Twins do not find out who at the horseback riding school keeps putting Mary-Kate's horse in the wrong stall and feeding it the wrong food. Original.

Ashley and Mary-Kate are having a terrific time on a family vacation in Washington, D.C. They especially like spending time at the Smithsonian Air and Space Museum. But during their visit, the famous Wright Brothers' plane starts to tremble -- and spooky voices float down from the cockpit! Could there be a ghost in the machine? Mary-Kate and Ashley are on the case!