Just as a pterodactyl emerges from a 150 million year-old egg to pterrorise (sorry) Ptaris (sorry again), Adele is in Egypt robbing a tomb of a mummy for reasons which become apparent later. This is a great opening, full of terrific scenes. Alas, after that the pacing slows down. While not without its pleasures -Adele's succession of failed attempts to break someone out of prison, the dead sister with a hairpin through her head who is kept in bed at Adele's apartment- it lacks narrative drive which all contrives to create a languid impression which taints the whole film and there were times when I felt myself dozing off.
There's a lot to like here, many vivid imaginative touches, wry humour, a touch of French cynicism, it almost, but just doesn't, succeed. Still, give it a try, there really is much to enjoy.