The Wings of a Butterfly (audio story)

The Wings of a Butterfly is a 2010 audio short story written and performed by Colin Baker for Big Finish, and featuring a companion-less Sixth Doctor. Written in about the year 2000, and previously published in the unlicensed anthology, Missing Pieces, the story explores the Doctor's willingness to change the flow of time in ways not authorized by the High Council of the Time Lords.

Summary
Visitng Gallifrey to attend an academic conference, the Doctor's old friend and mentor, Duotheros, requests that he use the TARDIS to examine a temporal anomaly centered on Bixor. The planet, once thriving, appears to have mysteriously eradicated itself, substantially reducing the number of people interested in buyind Duotheros' definitive history of that sector of space. Will the Doctor's investigations reveal the cause? Or does Bixor's untimely demise have something to do with a certain blue box?

Characters

 * Sixth Doctor
 * Duotheros, a fellow Time Lord

Continuity

 * An important aspect of this story's continuity is the fact that it was written long before it was recorded. Its total dearth of continuity references is thus understandable, as initial work on the story began before Big Finish even existed.  It's unclear exactly when Baker started writing the story, but the fact that it began as a Gary Russell commision for DWM, indicates that it likely predates most, if not all, of the novel ranges, too.
 * The Sixth Doctor's attitude towards changing history is the polar opposite of that expressed by the First Doctor in The Aztecs.

Timeline
The Wings of a Butterfly contains no reference to any companion or any televised or audio adventure. This indicates general placement somewhere between The Trial of a Time Lord and Time and the Rani, most likely between when the freshly-acquitted Sixth Doctor took Mel back to his older self, and the time that the Doctor first met Mel. Thus, it could be said to take place between DW: The Ultimate Foe and PDA: ''Business Unusual.