I don't mean to keep harping on this, but each episode of this story gives me another reason to appreciate the sheer anger of Tom Baker's Doctor in this story. His berating of Dunbar and Thackery in order to get them to listen to him is full of fire, and to see this Doctor use brute force to knock out a limousine driver seems out of character.
But that's what The Doctor in The Seeds of Doom is like. He is almost an antihero - a role rarely seen since the very early William Hartnell days. This story is the last of Season 13, the last story of this particular production block, and the last to see a Doctor this edgy.
Elisabeth Sladen sees Baker raise his game, and so she does her best to match his growliness, especially in the afore-mentioned scene in Thackery's office. We're also briefly introduced to the dotty Amelia Ducat, and we finally see Harrison Chase strut around his mansion in full glory, conducting electronic symphonies, praising his plants, and being the best and closest facsimile to a James Bond villain that Doctor Who would ever see. In fact, while the Jon Pertwee's era was often (inaccurately) compared to Bond, The Seeds of Doom is probably the closest Who cousin to Ian Fleming's secret agent.
The Seeds of Doom is bloody brilliant thus far, driven by its actors who are helped along themselves by a smashing script.