Synopsis: The Doctor and Rose land in Venice. While reading the entry about Venice in The Space Traveller's Guide (no doubt a sly reference to The Hitchhiker's Guide to the Universe), notes a mystery. There's a grand new opera building in Venice which receives no mention in the Guide.
Investigating, the Doctor and Rose encounter Fred Gobbo, a man the Doctor recognizes as one of the best musicians who ever lived. Oddly, though, he's a busker on the streets of Venice with no musical ability whatsoever. Nevertheless, the Doctor drags Gobbo and Rose off to the opera.
The opera on offer that night is something called the "Automatic Orchestra", a mechanical device that produces music so sublime that the Doctor notes it has mathematical precision. Curious, the Doctor and company go backstage to discover the Orchestra's secrets. When they do, they find that the orchestra is of extra-terrestrial—and specifically, Rokathian—design. It derives its musical power from sucking the musical talent from human beings attached to it.
A man, Magrillo, appears to take credit for building both the Orchestra and the opera hall. He tells of encountering a fallen star which gave him the power to create both.
The Doctor, however, suspects something quite different was behind everything. The Rokathians, he explains, are aliens whose entire society revolves around music. The "star" Magrillo encountered wasn't a celestial body at all, but a black box recorder from a downed Rokathian spaceship. The Automatic Orchestra was not simply creating music, but instead sending a distress signal back into space to the Rokathian home world. Magrillo, having none of this rational explanation, prepares the Doctor and Rose for integration with the machine, which eventually will kill them.
The Doctor wonders why Gobbo hasn't been selected for similar treatment, when the answer comes to him. Only humans with musical talent are suitable candidates for inclusion. Having sussed things out, he tells Gobbo to sing directly into the machine. This causes the machine to destabilize, and all remaining living humans to be released from its grip. It also begins an inevitable countdown to the Orchestra's firey demise. Before it explodes, however, it directs its signal against Gobbo, in one last attempt to protect itself.
Gobbo becomes infused with the essence of musical ability.
After a massive explosion, the Doctor and Rose have a short chat with Gobbo.. They ask for one last tune from the busker, and now his music is pitch perfect. His destiny as one of the greatest musicians who ever lived has now been put fully in motion. The Doctor and Rose leave, apparently destined for a quick trip to Liverpool's famous Cavern Club.
Notes: The book's lone comic strip.
To the keen Doctor Who fan, it's notable for three reasons.
First, it's Jonathan Morris' first comic-writing duties for Doctor Who. Second, Morris, a long-time contributor to the "classic" series of novels, had never written anything for the Russell T. Davies version of Doctor Who prior to this comic. And third, the title may be a deliberate reference to a long-held, but totally false, fan rumor that there was a story called "Opera of Doom" that was written, but never filmed, for the Sixth Doctor's era in the mid 1980s.
According to the rumor, "Opera" would have included a whole spate of very popular characters in one giant "everything-but-the-kitchen-sink" battle. Morris' choice of the title is therefore conspicuous in light of the fact that the television season which this book commemorates finally produced the long-awaited Dalek/Cybermen battle that every fan has hoped for, but no-one ever thought would happen.