The main problems are that the 'Nids weren't encountered until M40 (Behemoth, Macragge and all that), and they're moving into the galaxy from the Galactic East, and from underneath the Galactic plane.
A lost fleet is a nice idea though. Howabout a splinter of Kraken, which simply disappeared around the time of the Ichar IV (sp?), Iyanden, and the attack on the Scythes Of The Emperor. That's still a long time to be missing for. They could then re-emerge anywhere in the galaxy, just don't make them seem to be the size of one of the full Hive Flets. Either that, or they could be a forward element of Leviathan.
|