You remember the boat you heard taking soundings on the deep-water reach?
Of course you do! Well, I sent that information to the proper quarter, and since then watch has been kept in the woods just above it.

Last night only the coastguard police caught four men at it--all Germans.

They tried to escape as they did before, by rowing down the river, but there was a steam launch below which intercepted them.

They had on them a chart of the reach, with soundings, nearly complete; and when they searched their houses--they are all tenants of your astute father, who merely laughed at us--they found a very decent map of certain private areas at Harwich.

Oh, I'm not such a fool as I look.