Martha Jones is a bit tired of walking around in circle with the Tenth Doctor, who is using a small hand-held device to track an etheric beam in a busy town high street. She decides to take a break and grab a coffee. It's a beautiful summer day and the Doctor is happy to head off on his own, leaving Martha to take a seat. As Martha sits with her coffee and cake, she watches people going about their everyday lives and notices the repeated appearances of an old lady. Nothing special — an old lady, white hair tied up with a pin, brown cardigan and black handbag. Yet whenever she sees her, the same old lady is somewhere else, walking one way then the other, going in one shop and out another. At one point she sees the Doctor nearly knock her into the road as he blindly tries to track his signal. Martha decides to follow the old woman into the back of an antiques shop. She finds a room full of the same little old woman, about twenty of them, all sitting around knitting with "invisible" wool! As she is about to leave, her way is blocked. One of the old ladies pulls a gun on her. They are aliens in disguise, using their "needles" to generate etheric energy. With their energy levels low after landing, they decided on one common disguise. Their analysis of human behaviour indicated that little old ladies were the best choice, as they all looked the same and were unlikely to be noticed. The knitters continue to create their etheric energy as the old lady with the gun prepares to fire at Martha. Martha ducks and knocks the gun flying. A stray shot, shooting blue lightning, causes chaos. One of the old ladies drops her needles. As they roll to the floor, the ends touch and a green glow spreads to the other needles. The old ladies cry out as their power fades. The light spreads and the creatures' true forms begin to show: spindly front legs, segmented eyes, like giant grasshoppers. Then they all disappear. Without their report, their fleet passes by the Earth. Martha rejoins the Doctor, who is disappointed the etheric beam has disappeared. As they head back to the TARDIS, the Doctor sees a baby in a pram outside a shop. As they pass he comments on how strange it is that all babies look the same!
- The Doctor uses an etheric beam locator. The story does not directly name the device this, but the Doctor uses it to trace the energy from an etheric beam.
- The original short prose fiction featured in the Doctor Who Files series of hardbacks from BBC Children's Books was officially sanctioned by the Doctor Who production office.
to be added