"There, stick that in an envelope and post it. You're clearly not
fit for service afloat till that swelling goes down."

Nicky-Nan duly posted the certificate, which Dr Mant had
characteristically forgotten to date. After a week it came back with
an official note drawing Nicky's attention to this, and requesting
that the date should be inserted.

"Red tape," said Nicky. He borrowed a pen from Mrs Penhaligon, and
wrote the date quite accurately at the foot of the document.

Then, for some reason or other, his conscience smote him. He put off
posting the letter; and at this point again fortune helped him.
Word came to him by a chance wind that the staff of the Coastguard
had been shifted, over at Troy. Also (though he never discovered
this) the Chief Officer of Customs, after returning the certificate,
had left for his summer holiday.

So Nicky-Nan kept it in his pocket; and nothing happened.

The next year--so easy is the slope of Avernus--Nicky-Nan, who had
felt many qualms over filling in a date which (though accurate)
should by rights have been filled in by the Doctor, felt none at all
in adding a slight twiddle of the pen which changed "1912" into
"1913"; by which he escaped again, and again went undetected.

It had all been contrived so easily, and had succeeded so easily!
Everything said and done, his leg was worse. Any doctor alive, if
brought in, would bear witness that it incapacitated him.