Like the drugs at the heart of the late Harvey Wratton’s empire, The Shadow Line has become addictive in a slow, almost sneaky manner. After an unhurried, take-it-or-leave it start, it has insidiously built up to the point where now, three episodes in, it has become impossible to break free of its grip.

The principal problem with The Shadow Line is its identity crisis. At times, it’s a fascinating noir-ish thriller; at others, it feels like an unwieldy Shakespearian melodrama that has somehow lost its way en route to the RSC and found itself on the telly instead.

Appropriately, given that it begins with the discovery of a body, the opening episode of The Shadow Line moves at a pace that’s almost funereal, although that isn’t to say it’s boring.