Ace, bored, wanders the TARDIS. After finding a laboratory and a room full of jigsaw puzzles, she finds a zoo. She notices one of the animals is a dodo, which are extinct in her time. She sets it free, but it bites her and runs away.
Ace gives chase. The dodo goes through a hole in the floor, and Ace follows. She ends up in a large room full of clothes. She notices a large mirror. She sees a brown robe on the floor and tries it on, looking at herself in the mirror. Suddenly there is someone in the mirror. He reaches out his hand, and it comes out of the mirror. He asks Ace questions about the Doctor.
He starts to explain that sound and images coalesce into echoes, but before he can explain further who he is, the dodo appears and charges straight at Ace. She wraps it up in her jacket, but when she turns back to the mirror, the image is gone.
Ace later ponders whether the figure in the mirror is the echo, or is something else the echo?
- Ace finds the TARDIS laboratory and the TARDIS zoo. She once found a painting of Vincent van Gogh with a bandage on the other ear to the version she'd seen in books.
- She compares the TARDIS laboratory to Frankenstein's lab, "but with better lights".
- There is a "food dispenser thing" near Ace's room on the TARDIS.
- Ace could never operate the showers aboard the TARDIS, so she cleans herself in the sink and uses lots of deodorant.
- Stored in the multiple storage rooms on the TARDIS are the arms from the Venus de Milo, and bits of Apollo 11's moon landers.
- Dodos come from Mauritius, in Africa, but are extinct in Ace's time.
- This story is narrated by Ace.