I don't think the plot was over-complicated. Over contrived, maybe, but i guessed what would happen next virtually throughout the programme, even down to the fact that Michael Gambon was the father of the 'adopted' baby. I agree with the mumbling and some of the dialogue we could hear plainly was superfluous. When the nurse took the newborn into the orphanage, the sister said, "And this will be the newborn baby?" To which the nurse should have replied, "No. This is a packet of cornflakes."