A secretly gay detective in the 1940’s must investigate the murder of the man with whom he had a love affair with.

I think CraigDGriffiths makes an important point. ?His superiors and peers think it's a routine case, expect him to wrap it up quickly after a pro forma inquiry because, as CraigDGriffiths says, the victim was "only a fag, why do you care?" ?But he won't, he can't for reasons he can't confess to anyone.

And I always thought it would work better if they were still lovers, not ex-lovers. And both of them could be married, too.

Whatever. The appeal of the premise is that there is no lack of ingredients to stir into the plot.

"The imitation Game", so much of the story revolves around Alan being gay. It drives his actions as well as opening him up for blackmail. Its not an audience device, it's a character motivation.

I can see so much gold to mine here. When he wants to push on he gets asked "he was a fag, why do you care?", then "why aren't you married Jones?"

It's not a tada, it's a constant threat to the MC.

I agree with Foxtrot, to some degree.

Once the MC is established as gay and the audience get over the: 'OMG he's gay in the 40s' aspect, it's just another 'who dun it' only with a gay twist. I think the added complications as a result of the detective being gay need to be exploited more, and the connection of the dangers from the case to the MC need to be clarified.

What if the story took place in 1937, a year before Hitler became Time Magazine's man of the year, and the married gay lover was killed by American Nazi sympathizers?
The gay detective will have to go into the lion's den in order to catch the killers and put them away.