Professor Yessir tries to automate his friends to save everyone time, but when Bearwolf and Fidget come and find him, he discovers his big birthday machine has something very important missing.

Professor Yessir's Birthday Machine is one of seven stories in verse from the series "The Adventures of Bearwolf" by D. C. R. James.

“For three hundred and sixty-five days of the year
The Professor was working, that much was clear.
Outside his garage, a sign on display
Said, “Probably busy. Keep out of my way!”

Professor Yessir happens to be born on the 29th of February, which suits him fine because he's not really into celebrating birthdays with all those presents and cake. No, Professor Yessir just likes to show off all the things that he has made. So, instead of a normal birthday party, the Professor puts on a Great Exhibition whenever it's his birthday. He invites everyone to come along and press lots of buttons and see what they do.

Bearwolf and Fidget go to the Professor's exhibition whenever it's on. Fidget, especially really loves it. She gets so excited about going that she usually can't get to sleep the night before and stays up all night.

But one year, their invite just doesn’t arrive. So Bearwolf annd Fidget decide to go along and find out what is going on with the Professor...