Who is Roger Crosse from Noble House: A Novel of Contemporary Hong Kong and what is their importance?

Special Intelligence director, Roger Crosse, is in his fifties and is a part of Sevrin. He is valued by the Soviets, who develop an escape plan is he is detected. Roger Crosse is actually Arthur, an identity the Soviets have mistakenly linked to Jason Plumm. Crosse has used Jason (his alias) as a front since WWII. Crosse is a triple agent.