This is another Blake & Mortimer album. Set in the 1950s, its a stand-alone album by their creator E.P Jacobs.
While published as the 12th volume, it's actually the 7th.
In this album, Mortimer & Blake are exploring a cave on an island in the Azores, when they stumble on the lost continent of Atlantis, a lost high-tech civilization. But Orlik is there, and they are involved in political intrigue among the Atlanteans.
2 more albums are planned for 2012, the most recent 2 Blake & Mortimer albums (by Van Hamme and others). That will leave 6 more albums that could be done in 2013 and 2014, but they haven't announced them. These would ALL be albums done by EP Jacobs!