Penny Wise, Pound Foolish (audio story)

 was a 2011 Big Finish Productions audio short story read by David Troughton.

Summary
Showing too much interest in a mining operation on an almost deserted planet leads the Doctor and his companions into danger.

Plot
Jack returns to his cabin on the planet Juno 10. The Second Doctor, Jamie McCrimmon and Zoe Heriot arrive and convince him to let them inspect the twenty-metre wide hole that Jack is guarding on health and safety grounds. He watches as the trio peer over the edge. A second hole opens behind them, and they fall in.

Returning to his cabin, Jack watches the trio on a computer monitor, pondering on how they're still alive. Zoe notes the slimy ground they're on broke their fall. The Doctor thinks it is not a hole, but some sort of maintenance or supply tunnel. They hear a distant mewing noise and head toward the sound, hoping it leads to a way out. In his cabin, Jack continues to watch them on his camera. He plots to kill all three, declaring aloud that they are in his caves. He programs a two-minute system flush with hadron gas, only to find that the load had already collected is already significant. He launches a rocket to deliver the collection but the rocket falters and explodes upon launch.

Exiting his cabin, he heads to the crash site. He enters the wreckage and see red eyes throughout the craft. The Doctor appears in the doorway and advances on Jack with his companions. Zoe tells Jack she accessed the rocket by bypassing a keypad and they used the ejector seats to escape the crash. Jack names the creatures as Halflings, a hybrid species designed to mine branzine. Jack tells them that he is using the money he makes to buy more planets and carry on the mining. The Halflings begin to surround Jack and the Doctor thinks of an idea. He asks Jamie to prepare Jack's transmat.

On Paradine Alpha — one of Jack's planets — Jack begins to wake up. He immediately becomes aware of where he is and rages in anger at his entrapment.

Characters

 * Second Doctor
 * Jamie McCrimmon
 * Zoe Heriot
 * Jack

Worldbuilding

 * Juno 10 has two moons.
 * Jack is a Larian, with a little bit of Terian on his mother's side.

Continuity

 * Zoe continues to display intelligence on a par with the Doctor. (TV: The Wheel in Space)