Complex sentence: He also played Doctor Who companion Bernice Summerfield's father, Isaac Summerfield, in "Death and the Daleks", and he guest starred in the Big Finish Productions Doctor Who audio drama "Excelis Decays".
Split into simpler sentences: He also played Doctor Who companion Bernice Summerfield's father, Isaac Summerfield, in "Death and the Daleks". And he guest starred in the Big Finish Productions Doctor Who audio drama "Excelis Decays".