Right now we're in a situation in which one player is staking their life on another player being mafia. This means we are practically guaranteed to have at least one mafia between Dm, sky, and the person (if any) who contacted sky. The probabilities of us getting to this situation don't matter, because here we are. An important piece of information is that sky targeted me with a Supply Crate last night. This means two things. First, sky cannot have found Dm as mafia on her own. Second, sky is highly likely to be town because giving away a Supply Crate is obviously really bad to do as mafia. If you choose not to believe me, that's fine.
That leaves us with three scenarios, and two possible lynches.
1. Sky is mafia and Dm is town.
Obviously no mafia would out themselves just to kill a random town, so the only way this makes sense is if they knew Dm's role, which is unlikely, and Dm was an Agent, which is also not likely. This is what you believe if you want to lynch sky.
2. The third person is town and Dm is mafia.
This is the scenario I believe to be true. This is completely plausible, as that person has a 12/16 chance of killing a mafia for free due to sky being town. The other options are to publicly out themselves or keep that information to themselves. If that person was one who sky asked to vote on Dm, that makes it more likely that they would trust sky when they found Dm was mafia. Lynching sky is bad here.
3. The third person is mafia and Dm is town.
Lynching sky is still bad here. She would die without revealing the name of the third person and we would have let a mafia get away, and possibly lynch Dm too. This is also not likely to happen without mafia knowing Dm is an agent.
To summarize, if you want to lynch sky then you must believe that Dm is an Agent. Lynching sky is the only way that we can not catch a mafia. As an added bonus, I will stake my life on sky being town.
It's clear what we have to do.