Materialism's Conundrum with Determinism

Wether it is a clockwork or a computer, a materialistic universe is typically envisioned deterministically, even if this is not made explicit by the ones theorizing. Wether it is the biological basis of human behavior, the working of genes and memes on human society, any respectable and recent scientific theory dealing with people does away with free will. This is really quite a pity, as without it there is no true science, or truth in general. If our cognitive processes are indeed determined and any shred of free will an illusion, then it cannot validly be stated that we have developed a new theory, debunked some religious myth, or done any other great deed of scientific exploration. Our finding one idea superior to another would be just as much the product of determination and inevitability, as if it had happened the other way around. A second independent researcher verifying our data or failing to - determination, not proof that we are correct. Ten, a hundred, all scientists believing the same thing - the meme has won, not the truth. Of course, me writing this blog, you agreeing or disagreeing, maybe laughing at my simple reasoning, or marveling at the depth of my understanding - all meaningless and irrelevant. It is determined like the rest. Truth and lies, good and bad, beautiful and ugly, all goes by the wayside of inevitability.
One might even conceive of a situation where a certain truth, e.g. the existence among us of a parasitical race of mind-draining martian vampire zombies, along with all their activities, is concealed from everybody while in full plain view, simply because these alien derelicts have found a way to prevent our deterministically functioning brains from ever registering them or their doings. A bunch of them might right now be feasting on your boy/girlfriend’s brain and you might instead perceive - her fainting? stumbling? feeling weak and nauseous? having a seizure? We will never know, will we, for there is no way to pierce the shield of causality that imprisons our consciousness?
Is there a way around? Many things have been proposed, from quantum indeterminacy to blissful ignorance of the problem. I am not sure if the future might be able to show that the laws of causality break down, or at least loose their timeline in complex feedback systems with self-awareness, like our brains are. After all, our ideas of causality are mainly assumptions validated on systems lacking complexity. However, if complexity can bring forth truly novel qualities, like indeterminism in the sense that there are no time-linear simple processes accounting for the outcome of the whole system, then I believe we have broken a big chunk of scientific dogma. It also means that materialism is not the be-all/end-all of creation, that there are significant events that do not fit into its explanatory framework.