As a result of their work together, Montfaucon later recommended Rigby's services to a colleague of his (theorized to be Hugo Waldegrave). As seen in the letter from The Crypt, this benefactor went on to hire Rigby in order to retrieve a rare Null artifact from a tomb. Despite Montfaucon vouching for Rigby's character, the unnamed author of the letter looks down on Rigby as a man of poor breeding and character and warns him not to attempt to use the artifact himself.
These warnings apparently went unfounded. The words “ENORMOUS VALUE” and “power” are emphasized in red pen on the letter, most likely by Rigby himself. It is evident that Rigby ignored the words of his contractors and attempted to claim the Null artifact for himself.