Simply put, Evidence: The Last Ritual is one of the stranger games you're ever likely to play. That doesn't make it totally awesome, as players of the only game that even remotely resembles it - the failed PC experiment Majestic - will tell you. But it ain't at all bad either.
This is the sequel to 2004's lamely titled Missing: Since January (and its pseudo-expansion pack, Missing: The 13th Victim), and the gameplay and background are roughly the same as in the original. To wit: there is a fearsome serial killer on the loose in Europe who calls himself (or possibly herself?) The Phoenix, and who leaves behind CD-ROMs to taunt the authorities. Apparently, old gimmicks like a playing card, a note made up of cut-and-pasted magazine letters, or a pupaescent moth have been washed away by the flow of technology.
Anyhow, the discs contain a series of puzzles, and the theory goes that by solving the puzzles, you'll help catch the killer. At the beginning of the game, you're inducted into the "ICPA," the International Committee for the Phoenix's Arrest, a large international group of sleuths working together to crack the discs.
Here's where the weirdness comes in. Unlike more conventional adventure/puzzle games, Evidence requires a functioning email address and a connection to the Internet. Once you've started the game, the hunt for clues to solving the puzzles often require a substantial amount of real-world Googling, and you can expect to receive regular messages from the ICPA, in real time, while you play (along with - predictably - taunts from the Phoenix himself).