What is the relationship between the
Un-space Exploration Committee and
Group27, if any? Are they one and the same, or not?
Group27 studies and fights conceptual fish and Mycroft Ward; whereas the Committee is "responsible for mapping, charting, researching and exploring un-space". Aside from Scout (unofficially) working with both these groups they don't seem to have very much in common at all, although the Committee is apparently aware of Mycroft Ward. (pg.163, UK hardback)
Eric seems to be under the impression that Dr. Trey Fidorous is a member of the Committee: "Maybe someone there would be able to help me track down Dr. Trey Fidorous". (pg.106, UK hardback) Indeed, why had they helped the First Eric Sanderson on his journey to find Fidorous?
Fidorous only ever claims to be the last surviving member of Group27, following Ward's attack: "I was the only Shotai-mu to survive". (pg.282, UK hardback)
The Un-space Committee on the other hand, according to Scout, are choosing to ignore Eric's business cards out of fear of Mycroft Ward. (pg.163, UK hardback)
Other than serving as a "rabbit hole" through which Eric can enter Wonderland, the Committee doesn't make much of an appeareance at all; the last time they're mentioned is on pg.181 before Eric and Scout break into Waterstones.