Wizard and glass - Stephen King

The Dark Tower beckons Roland, the Last Gunslinger, and the four companions he has gathered along the road. And, having narrowly escaped one world, they set out on a terrifying journey across the scarred urban wasteland to brave a new world where hidden dangers lie at every junction: a malevolent computer-run monorail hurtling towards self-destruction, Roland's relentlessly cunning old enemy, and the temptation of the wizard's diabolical glass ball, a powerful force in Roland's first love affair. A tale of long-ago love and adventure involving a beautiful and quixotic woman named Susan Delgado.

And the Tower is closer...