Pulling up the stakes

As far as I can tell, "Please Shut the Gate" is Stephen Lock's sole contribution to Doctor Who and it is a rather short Short Trip.

The TARDIS lands on Mars in December of 1999. There are no Ice Warriors about and instead our heroes find a tent and the remains of a campsite. Upon seeing a pipe - his pipe - the Doctor recalls that he had brought Ben and Polly here to see the Martian sunrise back when he was William Hartnell. But, while they were roasting marshmallows, the lateral drift compensators kicked in and they had to scramble lest the TARDIS leave without them.

Jamie and Zoe hear what they think are the sounds of a bombardment but the Doctor knows that those are the sounds of Martian probes landing. He also realizes that his former campsite would be an awfully big anomaly for the Earth probes of the 20th century so he enlists his companions in a hasty attempt to disassemble the old bivouac before a probe lands nearby and starts taking photographs that would make a good recruitment tool for the Boy Scouts but pose an existential crisis for humanity.

They are mostly done when the probe crashes right on top of the TARDIS and falls to the Martian surface in a state of severe disrepair.

At a mere 8 pages or so, this is truly a short trip. While insubstantial, it's still a short burst of fun to picture the TARDIS crew scrambling out of their asses to break camp and trying to stuff everything in the ship before doing something to cover their footprints and making a quick getaway.