A Goodreads user asked:
Okay I’ve been wondering, is Taranis the father of Alastair? Because all the babies were supposed to have 3 fathers each, but then Hamilton writes, “His... name is Alastair... and his two genetic fathers, Doyle and Frost.” All the other babies have three fathers like they’re supposed to. So is Taranis one of Alastair’s fathers? Please remember this happened in a time of wild magic, anything can happen.
Sarah I think that Taranis is one of the fathers. When Merry was talking to Trancer in the end of the book, Trancer claimed that Taranis is father to at least one of her children and Merry's response was that it was ironic. She goes on to explain that there was another way of dethroning a king besides being infertile.
Elizabeth Ortiz I kind of assumed that since Frost and Doyle are the favored of her men, and they love each other that they are special and therefore get to share being Alastair's father between the two of them and not with a third lover. Just what I thought.