Our Last Crusade or the Rise of a New World, Vol. 4 (light novel‪)‬

A SECRET NEVER TO BE TOLD...To rest and recuperate from their set of life-threatening missions, Unit 907 is finally granted a much-needed break. And what better place to spend time off than at a distant resort where they can lounge in their bathing suits 24-7? Against all odds, the trip is going according to plan…until Iska bumps into a certain witch who instantly reminds him of Alice. In fact, it feels all too familiar when she demands he come to Nebulis—for reasons she simply cannot reveal. And she isn’t the only one with a hidden motive: Alice has arrived to investigate why her sister has been spying on Iska…for months.