The Doctor and his Adventures

The 10th Doctor is at it again when an adventure gone wrong leaves him and Martha stranded on an alien planet surrounded by water.

The two are totally stuck, no Tardis, no screwdriver. Just them. That is until a familiar friend finds the Doctor, and Martha is totally stunned at how close the two seemed to be.

Martha is determined to learn the story of the stranger and the Doctor whilst the three do their best to find the Tardis and get off planet before the planet explodes.

Did I mention the stranger is a mermaid?

(The story will switch between the past and the present with all the juicy bits in between.)