No one is likely to accuse Netflix’s new limited series Eric of a lack of ambition. Starring Benedict Cumberbatch and created by British playwright and TV veteran Abi Morgan (River, The Split), it fairly crackles with aspirational energy. The problem is the series’s utter inability to find a coherent tone. Imagine Mrs. Doubtfire embroiled in a nightmarish conspiracy, and you will have some idea of why Eric fails.