Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Title | Author | Doctor | Companion(s) | Published |
| --- | --- | --- | --- | --- |
| Time and Relative | Kim Newman | 1st | Susan Foreman | November 2001 |
| Citadel of Dreams | Dave Stone | 7th | Ace | March 2002 |
| Nightdreamers | Tom Arden | 3rd | Jo Grant | May 2002 |
| Ghost Ship | Keith Topping | 4th | None | August 2002 |
| Foreign Devils | Andrew Cartmel | 2nd | Jamie McCrimmon and Zoe Heriot | November 2002 |
| Rip Tide | Louise Cooper | 8th | None | January 2003 |
| Wonderland | Mark Chadbourn | 2nd | Ben Jackson and Polly | April 2003 |
| Shell Shock | Simon A Forward | 6th | Peri Brown | June 2003 |
| The Cabinet of Light | Daniel O'Mahony | Unspecified Doctor | None | July 2003 |
| Fallen Gods | Jon Blum and Kate Orman | 8th | None | August 2003 |
| Frayed | Tara Samms ( pseudonym for Stephen Cole ) | 1st | Susan | October 2003 |
| The Eye of the Tyger | Paul J. McAuley | 8th | None | November 2003 |
| Companion Piece | Robert Perry and Mike Tucker | 7th | Catherine Broome | December 2003 |
| Blood and Hope | Iain McLaughlin | 5th | Peri and Erimem | January 2004 |
| The Dalek Factor | Simon Clark | Unspecified Doctor | None | February 2004 |
Question:
What is the companion for the author Dave Stone?
Answer:
Ace