The actress's character Anne Foster was last night (March 19) unveiled as the culprit responsible for the death of villainous Frank, her own son.
However, speaking on Lorraine today, Taylor confessed that she only discovered the twist when co-star Andrew Lancel - who played Frank - tipped her off during filming.
Taylor explained: "It was strange, because I didn't know when I signed on that it was going to develop so brilliantly. But a little while after, Andrew was telling me that he was leaving at a certain point.
"I asked, 'What happens?' and he said, 'I get killed - and between you and me, you are very deeply involved!' So he slipped me the wink quite early, so I had the excitement of knowing that the scripts were working towards a wonderful denouement. It's just such a gift for an actress, and I've loved every moment of it."
The 73-year-old added that she "loved" filming her showdown scenes with Alison King, who plays Frank's ex-fiancée Carla Connor.
Discussing the plot climax, she continued: "I was helped very much by Noreen Kershaw who directed those episodes. It is exhausting, and you always pray that the sound and the cameras are on form when you are.
"The worst thing is if you have to do it again, because the lighting or the sound went wrong. Sometimes that's what gets you, because you have to dredge it up from somewhere.
"But in this case, it all went quite well. I'm quite pleased with it, which is quite naughty, to be pleased with your own work!"
Coronation Street continues on Thursday (March 22) at 8.30pm on ITV1.
> Coronation Street spoiler: News of Frank's killer stuns the street
> Corrie reveals Frank Foster killer, Digital Spy readers solved mystery
> Coronation Street Frank Foster killer: It's a relief to be unmasked
> Coronation Street Gwen Taylor: 'Anne's behaviour was terrible'
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