Mister Fantastic
At a memorial service for Bob Reynolds, CLOC remarks he would rebuild the Watchtower (which vanished at the moment of Bob's apparent death) at an undisclosed location in preparation for the return of the Sentry, and that no one would be allowed to approach it. CLOC then gives Mister Fantastic the Sentry's diary and instructs him to read the final sentence of page nineteen, the contents of which Reynolds knew that only Mister Fantastic would understand. When asked about it, Mister Fantastic keeps the information to himself.