Skipping like stones over the sea, the penguins left. Nobody saw them again.
There were photographs, drawings, videos, of course. Children were as familiar as ever with the penguins; more so, if anything, on account of the mystery. Where had they gone? And why? The dodo had been a tragedy, but this was simply unfair: generations robbed of penguins, a waddling gap in the pantheon of zoological curiosities.
Pools stood empty in wildlife parks. A famous biscuitmaker changed its brand to Puffin; the original bars changed hands on eBay for thousands of dollars a pack.
The penguins watched, and sniggered.