This was my first Cotton Malone novel and I think it shall be my last. The protagonist's previous exploits are amply advertised throughout this novel but I do not care enough to go through another one of these. And I will try to explain this without any spoilers.
The Charlemagne's Pursuit starts off promising enough, a sub in trouble and probably lost at sea. Cut to the hero about to pick up a package in a clandestine setup, at the high terminal of a ski lift. Of course all hell brakes loose. Of course the hero survives. And the pursuit begins. But it is hardly ...Charlemagne's.
I cannot understand why Charlemagne was dragged into this, besides providing a catchy title in a "Da Vinci Code" fashion. The story could unfold without the dead emperor's item as it holds no crucial hints and it provides no motivation to anyone. The entire "mysterious symbols / ancient writing" gives off a sense of mimetic attempt rather than add anything to the story. Both Cotton and his antagonistic companions already have a strong motivation to go on with their quest (in fact, no imagination was stretched in providing said motivation) and the records of the footsteps that are to be followed already exist.
What is never explained is why the nefarious bad guy is paying an expensive assassin to take out a number of people only to keep a secret that is not exactly...earth-shattering if it came out. The (minor) scandal would have been the covering-up and not the information that was supposedly protected - so why cover it up in the first place?
If you are the airport and are between this one and the latest Kathrine Neville novels, go for this one. In any other case, though, pass.