Thoroughly enjoyable. Well written, great casting, two leads pinged off of each other perfectly. Anna Maxwell Martin's drooped shoulders from a distance - superb - a tiny moment which expressed exactly what she had just discovered. An acting masterclass all through the series. A joy as usual watching David Mitchell's expressive face and contrasting indignation, contrition then sudden moments of enlightenment. The son a welcome newcomer, as were all supporting cast members throughout all episodes. Loved the other three detectives and their team work. Dipo Ola shone out - his performance quietly understated yet firm, sympathetic, a good foil against Mitchell. Mix of serious and comic was just right - some laugh out loud moments as well. Much praise to locations, sets and props people. Derek Jacobi of course stole his entire episode as soon as he spoke one word. One of my favourite performances ever was Dorothy Atkinson in "Mum" - she is very good in this one too - a scene stealer.