Exhibit C is a timeline, reconstructed to the minute, and its whole argument is a matter of geography. The forgery — the pressing of the traced plank into the ledger under the grate — happened at or about 3:47 in the morning, a time the prosecution fixed with some confidence and then, unwisely, wrote down. Writing down a time is a gift to an innocent frog, because a frog can only be in one pond at a time, and PeePoo, at 3:47 AM, was demonstrably in a different pond. Three of them different, in fact. The ledger is here. PeePoo was there. The exhibit is the distance between.
You cannot forge a check and cross three ponds in the same instant. Frogs are quick. They are not two-places quick.
Here is the reconstructed night. At around half past three PeePoo left his own pad — not to sign anything, but because he had spotted, across the water, a gnat of unusual quality catching the light. He crossed one pond, then a second, then a third, in the unhurried way of a frog with nowhere criminal to be, and he arrived at the reeds at roughly a quarter to four to admire the gnat properly. He was still admiring it at 3:47, the exact minute the plank met the ledger a full three ponds behind him. You cannot forge a check and cross three ponds in the same instant. Frogs are quick. They are not two places quick.
The corroboration is where the prosecution wanted to laugh and could not. The gnat itself — a witness of impeccable character and short attention span — was present for the entire admiring and has declined to testify, which is its right. But two things that cannot decline corroborated the hour anyway. The moonlight, whose angle at 3:47 falls only on the far reeds and nowhere near the grate, put PeePoo exactly where he says he was. And the booking stamp, applied later that same night, timed the arrest against the same moon and matched. When the sky itself is your alibi, the case has a geography problem it cannot cross-examine.
What Exhibit C proves is the one thing no tongue-print can: that the honest frog was elsewhere. Exhibits A, B, and D tell you the hook did the signing; Exhibit C tells you where the un-hooked frog was standing while it happened — three ponds off, in the reeds, being decent, watching a bug. A forger builds an alibi and it creaks. PeePoo did not build one. He simply had a nicer place to be that night, and the moon happened to notice.