The C.I.D. Investigation of Washington Irving
Catch-22The comedic investigation into who is forging Washington Irving's name on censored letters.
increasing
Bearing strength in each event
decreasing
Yossarian's censorship games

The Forger
The Letters
Yossarian censors letters, signing them "Washington Irving" or "Irving Washington." He also writes "I yearn for you tragically" and signs the chaplain's name.
The C.I.D. Arrives
A C.I.D. man posing as a patient arrives to investigate. He asks about Irving or Washington. The men know he is C.I.D. because he won't censor letters.
The Trail
The C.I.D. man is baffled. He suspects the chaplain. The investigation continues throughout the novel.
Major Major's forgery

The Second Forger
The Idea
Major Major, bored, begins signing Washington Irving's name on official documents. He enjoys it. The documents stop coming back.
The Second C.I.D. Man
A second C.I.D. man arrives, masquerading as a pilot. He confides in everyone. He suspects the chaplain. Major Major lies to protect himself.
The Confusion
The two C.I.D. men suspect each other. They both visit Major Major. The investigation becomes a farce. No one is ever caught.
Corporal Whitcomb's interference

The Complication
The Plot
Corporal Whitcomb, to help the chaplain, forges Washington Irving's name on a C.I.D. man's report. He thinks this will clear the chaplain, but it implicates him further.
The Chaplain's Fear
The chaplain is terrified. He is now suspected of being Washington Irving. The C.I.D. investigation intensifies.
The Interrogation
The chaplain is eventually interrogated in the basement. The investigation culminates in his mock trial. The forger is never identified.
During Yossarian's first hospital stay
After Major Major becomes squadron commander
When Corporal Whitcomb forges the chaplain's name