What's the deal with the cure delivery on the rooftop in Arkham City?

So I've been playing Arkham City recently. Near the beginning of the game,

The Joker poisons Batman.

Much of the rest of the game is spent

searching for the cure to the poison. At one point, you get a call from Alfred, who tells you that Lucius Fox has synthesized a cure and it's Coming Soon To A Rooftop Near You. Sure enough, the cure is in a delivery capsule just like the ones that brought me the BatSuit and the Turbo Grapple, but when Batman injects the cure, he passes out and wakes up at the Mad Hatter's Tea Party. The supposed cure is never mentioned again and the rest of the game centers around finding more cure?

What did I miss?

It's all part of Mad Hatter's delusion.

Mad Hatter specializes in hypnotic suggestion. We are told that finding a cure may take time and suddenly Batman receives a call that the cure is ready, only to find that it's actually a sedative. What happened is that by some sort of hypnosis , Batman is led to believe that whole part - the call, the delivery, taking the cure, etc. What probably happened is that the hatter planted a syringe with the poison at this location and led Batman there. (I don't believe we actually can tell when that hypnosis takes place but we do get a glimpse of the hatter when Batman rescues Vicky Vale, so it might have happened then)

In the cutscene where you rescue Vicki Vale, there's a quick cut of Mad Hatter adjusting his hat. Mad Hatter is a master of hypnosis and suggestion, chiefly through his high-tech hats; this is why it's so important for Batman to remove both his bunny hood and smash the Hatter's hat when he shakes the Tea Party suggestion. During the cut-scene, Hatter is planting the suggestion in Batman's head, which is why you get the "call" from "Alfred" immediately after the cutscene ends. Hatter doesn't know the details of what Batman wants, only that it's what he wants more than anything; right at that point, what Batman wants most is for Alfred to call and say that there's plenty of cure for everyone and there's enough spare that Batman can have some.

Neither the call, the canister or the cure ever existed.

The cure from the capsule was not real. It was a psychotropic drug created by the Mad Hatter that gave you the hallucinations of the tea party. The game implies that the Hatter either replaced the capsule or he faked the transmission and there never was a real capsule.

The main clue was that even if the Hatter knew when and where Batman would be getting the cure, he shouldn't have known that the cure would knock Batman out and make him easy to capture.