Watson stared for a moment before dropping his own trousers. "A swim," he repeated. "You really are mad." This was not swimming weather. It was far too cold for a quick dip, and they would be sent heading back home soaking wet and freezing.

Still, he quickly stripped down to nothing, and shivering a little, stood up straight to look Holmes in the eye. "Very well," he said. "A quick dip. I'll join you in this insanity." Not that there was anything unusual about that state of affairs; he usually joined Holmes in whatever mad schemes were current.

Taking a breath to prepare himself, Watson extended his hand for Holmes to take before they plunged in. "Promise me a warm bath when we return home."