Endnote 42: Marathe's pretend-to-pretend
The ‘thing of important’ seems to be that Marathe’s A.F.R. superiors believe he only is pretending to betray them in order to secure advanced U.S. cardiac-prosthetic technology for his wife; but that in fact he really is betraying them (the superiors, his country)—probably actually for that medical tech—and is thus only pretending only to pretend.
Context
The endnote that untangles Marathe's triple-agent knot — and the fulcrum of the whole geometry is a damaged body: Gertraude, born skull-less, her heart restenotic, needing "advanced U.S. cardiac-prosthetic technology" to keep beating. A legless assassin betrays his nation to buy his wife a prosthetic heart: the A.F.R.'s elective disability and the Concavity's inflicted deformity meet in one marriage. ("The ‘thing of important’" is Marathe's own English-idiom signature, quoted as written.)