Five seasons into Outlander and there are still no solid answers regarding Jamie Fraser's (played by Sam Heughan) ghost and why he was watching future wife Claire Fraser (Caitriona Balfe) getting undressed at her hotel window. Frank Randall (Tobias Menzies) was furious when he spotted the highlander but left confused when he seemingly disappeared into thin air as he walked up to him. Now fans have spotted a major plot hole regarding the moment.

Not long after Frank spotted the highlander's ghost watching Claire, his wife travelled back in time to the 18th century after touching the stones at Craigh Na Dun.

Claire found herself separated from Frank and spent much of her time at Castle Leoch trying to get back to the stones.

Unfortunately, it was revealed Claire was destined to spend more time in the past while Frank desperately searched for his wife.

Frank was shocked when he realised his wife had disappeared without leaving any clues as to where she had gone.