Galaxy Angel II Vol 2

From the Broccoli Books edition

When Milfeulle suddenly falls out of contact with the Rune Angel Troupe, it's up to them to get to the bottom of things, but they've got problems of their own. Nano-Nano and Brave Heart have been stolen by a treasure hunter named Anise! As if that weren't enough, things have grown tense aboard the Luxiole, as Apricot and Kazuya's relationship hits a rocky patch. And when a disturbing message arrives from an old friend, it's time for the Angels to work together like never before!

Source: Anime News Network Encyclopedia