“Tansy...Forgive me...the blood...oh, please...Tansy...Dead...You’ll have others...sweet babes and trueborn...be a good wife and the gods will bless you...sons...trueborn sons...aaahhh.”
--SoS, pg. 29
Those are some of the last words that the reader gets from Hoster until he dies several hundred pages later. But what do these enigmatic final utterings mean? Catelyn thought that her father might have been calling out to some old mistress, but, compared with other quotes, we can surmise a different story. Let’s look at a quote from CoK, pg. 571
“It was best,” her father whispered. “Jon’s a good man, good...strong, kind...take care of you...he will...and well born, listen to me, you must, I’m your father...your father...you’ll wed when Cat does, yes, you will...That stripling...wretched boy...not speak that name to me, your duty...your mother, she would...Oh, gods, forgive me, forgive me, forgive me...”
It seems that Hoster was talking to Lysa in both of the above quotes. But what is he talking about? We can figure out by simple observation. We learn at the end of A Storm of Swords, that Littlefinger impregnated Lysa, but Hoster secretly gave Lysa a draught that led to an abortion. It seems that he was asking Lysa’s forgiveness for this. The ‘wretched boy’ is Littlefinger. The tansy is explained by a quote of Lysa’s from SoS, pg. 913
“I gave you my maiden’s gift. I would have given you a son too, but they murdered him with moon tea, with tansy and mint and wormwood, a spoon of honey and a drop of pennyroyal. It wasn’t me. I never knew. I only drank what father gave me...”
The ‘tansy’ that Hoster is muttering is most likely the tansy that Lysa lists in the ingredients of the abortion drink.
There could possibly be another explanation for the mysterious last words, however. On SoS, pg. 331, Arya and the Brotherhood Without Banners come to the brothel in Stoney Sept. There, they are introduced to a whore named Tansy. Coincidence?
It has been suggested that Hoster had a love affair with this Tansy, possibly during his campaigns in Robert’s Rebellion, and he did something that led to him begging her forgiveness. While this theory has a certain romantic merit, it fails to stand up to the other explanation. The mutterings about trueborn babes, the blood, the wretched boy, they all point to Lysa’s abortion as opposed to an affair with a whore in the riverlands.
So it appears most likely that Hoster was referring to Lysa’s unknowing abortion on his deathbed. It could be possible that he was in fact referring to a whore named Tansy, but all evidence points in a different direction.