Crime dramas are nothing new: we mourn the passing of each one until something else comes along. The is good news for those of us recovering from the loss of Broadchurch, because its replacement, the new murder-mystery Fearless, arrives on TV tonight and is almost as good as its predecessor. But not quite.

Fearless has a cracking cast and a compelling storyline, which has been penned by Homeland and 24 writer Patrick Harbinson. But, despite all that, the new show's first episode just misses the mark. The acting is largely clunky, the characters unsympathetic, the baddies too obviously bad. Yet it's almost good. Just not quite there.

Helen McCrory, whom we know as exceptional from performances in Peaky Blinders and Penny Dreadful, takes the lead in the six-part drama as Emma Banville, a human rights lawyer who makes headlines defending paedophiles and terrorists. It's a thankless task. Only her boyfriend, played by comedian and TV host John Bishop, actually seems to like her.

Banville is recruited by the wife of Kevin Russell (Sam Swainsbury) to reopen the case that convinced him of the murder of a schoolgirl 14 years ago. Russell and his wife maintain that he is innocent. Russell's son doesn't seem so sure.

She is soon persuaded that Russell's lawyers are hopeless, and detectives begin to ask some key questions. She's prepared to go far down the road of unpopularity to prove her case, risking her personal life and career to defend this man. But, alas, she runs headlong into a (literally unbelievable) mass conspiracy. Five minutes of Sir Michael Gambon grace the end of the first episode – worth sticking with this opener through to its final minutes.

But don't let me put you off. Fearless is almost very good. Almost. And you could watch it... or you could binge-watch Broadchurch all over again, which is what we'll be doing.

Fearless airs on ITV 9pm Monday 15 June

by Helena Kealey