Break the Cutie: Usually, with Holmes, this would be a case of Break the Haughty. But his adventures with the Doctor had been, up to this point, softening him.
Darker and Edgier: Up 'til now, Holmes and Watson have been getting into no more trouble than Martha did in the original season. This marks the first time one of the Holmesian Companions takes the rap that the Doctor should have.
Serial Escalation: Though the Cerebus Syndrome doesn't kick in until "Dynamics of a Point", this is the episode that starts racking up the intensity.
