u/hoattzin

I thought that when using perfect tense and reflexive verbs, the te/se/me always goes before the haber, like “se ha duchado”, but in the book I am reading, the author has several times tacked it on at the end of the haber, like so: “Habíase acercado à la parte trasera de la víbora…” Is this a style of the author? an older version/ literary version? the book IS from 1942