It’s taken me nearly 40 years to suddenly think something different about Swansong.
I always watched it from the point of view that Katherine was planning to kill Pam. She was so unhinged that she’d
Come back to Dallas to kill her sister.
But of course I don’t think that’s right. Katherine was stalking Bobby and then seeing the two of them together and kissing just tipped her over the edge and that’s when she drove the car towards them both.
But what was Katherine doing back in Dallas? What was she planning to achieve?
Well she already attempted to kill Bobby by shooting him & she told JR when she was caught trying to poison Bobby at the hospital - "my life was over why shouldn't his be!" So it makes sense that at some point she would try again.
In Swansong I honestly think her original intention was to kill Bobby and you can clearly see that she (as the blonde woman in the car) was frustrated that Bobby spent the night with Pam. I can see her sitting in the car thinking first he's with Pam, then Jenna and now Pam again! What about me!?! He doesn't want me, well I'll soon put a stop to all that once and for all!!
When Bobby leaves in the morning she makes no attempt to knock him down. Clearly she has changed her mind who she wants to hurt now and that in her own words is going to be "sweet, darling Pam who everyone just adores!"
When she see's Pam step on to the driveway she quickly seizes the opportunity given to her and she speeds the car directly at Pam NOT Bobby but Pam. She now sees Pam as the greater threat and she can't abide the thought of the two of them back together. In her own mind with her life being over she finally decided she wanted revenge on her sister who was married to the man she loved. Bobby being the man he is dashes back to push Pam out of the way but not in time to save himself and get's hit by the car. At this point I honestly think Katherine was so unhinged that she had no control over her own safety, she doesn't slam the brakes on, her car just ploughs into the back of the gardeners truck. A classic scene, all the more poignant for being the way Patrick Duffy would leave the show.
As to why she was back in Dallas, well discounting the fact Duffy wanted to leave and the writers needed a good storyline to do it, I think it's possible she wanted to see how both Pam & Bobby were doing. More so Bobby because she was in love with him. It's just the realisation that the two of them might get back together really unhinged her mind to the point where she wanted to take revenge.
Pam cradles a fatally injured Bobby Ewing in one of the show's greatest episodes - Swansong.
