Gods and Fighting Men, by Lady Gregory [1904], at sacred-texts.com
ONE day Finn was hunting, and Bran went following after a fawn. And they were coming towards Finn, and the fawn called out, and it said: "If I go into the sea below I will never come back again; and if I go up into the air above me, it will not save me from Bran." For Bran would overtake the wild geese, she was that swift.
"Go out through my legs," said Finn then. So the fawn did that, and Bran followed her; and as Bran went under him, Finn squeezed his two knees on her, that she died on the moment.
And there was great grief on him after that, and he cried tears down the same as he did when Osgar died.
And some said it was Finn's mother the fawn was, and that it was to save his mother he killed Bran. But that is not likely, for his mother was beautiful Muirne, daughter of Tadg, son of Nuada of the Tuatha de Danaan, and it was never heard that she was changed into a fawn. It is more likely it was Oisin's mother was in it.
But some say Bran and Sceolan are still seen to start at night out of the thicket on the hill of Almhuin.