Mana Sensing

Jace allowed his consciousness to seep into the earth beneath him, to plumb its unfamiliar depths. And there, deep within these foreign lands, he felt the presence of others: Elemental spirits and ancient ghosts, born from or drawn to the soul of Kamigawa's lands, and they claimed much of its mana for their own. These must be the kami; Jace steered clear of them, lest they grow wroth and manifest in the world above.

So Jace allowed the merest dregs of the land's power to seep into his soul, and still felt more than a little run down after an hour's rest. Groaning softly, he forced himself upright, scowled at his cuffs, his sleeves, and the hem of his cloak, all now stiff with the residue of the muddy water in which he'd landed.

Baltrice gave him an exasperated look as he rose. Jace wondered briefly what he'd done to piss her off now and only then realized that it probably wasn't him. Perhaps she, too, had found her precious mountain less generous than she'd hoped.

Agents of Artifice (Magic The Gathering: Planeswalker Book 1) Chapter 13