The Death of John Collins: Cover me, I'm going in!

Let's get straight into it. Here's a cover concept I've been working on for 'The Death of John Collins':

It's not finished, and the text design is particularly negotiable - I'll be the first to admit I know nothing about fonts and formatting. That's the sort of thing that can be figured out later. What I'm really interested in right now is the concept and style; does it work? I'm thinking of doing hourglass-themed covers for books 2 and 3 as well, so that they make a matching set.

Art-wise, I think the 'glass' areas might benefit from some reflection markings to give them a bit more shape. Either that or the sand needs to be made flatter and more stylised. At the moment it's a little bit of a compromise between realism and iconography.

My main concern is that the whole thing might be a little too stark - harsh white text and art on a very dark background. Could it do with a little more variation? I'm a big fan of really stripped-down, conceptual/impressionistic book covers - I might well do a blog post about this in the near future - so I've probably erred on the side of contrast.

Please let me know what you think, either in the comments or on Twitter - all feedback welcome!

As a bonus, here's the blurb I'm working on:

"Some believe John Collins destroyed time. Now, in the last human city, Collins has returned, and three students must make their own judgements about his motives. One worships him; one has sworn to kill him; and billions of lives may hang on the decision of the third.

And Collins brings a warning: time is collapsing again."

Probably needs more polish than the cover, but again, comments welcome.

Finally, a shout-out to @MarijanJett and @Ralimore, who hosted me on their blog this evening as an experiment in drunk guest blogging. Find my post at http://taoz.net/blog/?p=132, and just generally check them out - excellent writing peeps and tweeps.