Nofel am Catrin yn cael ei bwlio ar dudalennau Facebook gan Jan. Ond pan mae Jan yn dangos llun arbennig i Catrin, mae'r ddwy'n dod o hyd i wybodaeth sy'n eu clymu am byth.
A novel about Catrin who is bullied on Facebook by Jan, but who, after delving into the dark secrets of the bully, reveals information which binds both girls together for life.
