The air had grown chill the minute they descended into the strange valley, which was unmarked on any of their maps. It was so strange here, devoid of animal life and completely silent. The horses were nervous the entire journey through the vale. As they set about to collect firewood for the campfire they could hear their own voices as dim echoes through the eerie silence.
The food didn't taste anything that evening and their sleep was cold and troubled by nightmares. While they are clearing camp the next morning, one of them stumbles over a piece of stone jutting out of the ground nearby the horses. On closer inspection there seems to be runes engraved into the polished surface. The symbols true meaning is no more known among mere mortals and if they decide to dig deeper, they will discover that it is an ancient altar buried within the soil.
Any historically oriented party member will recognize the largest symbol to be the insignia of the powerful warlock who ruled this realm several centuries ago. At their departure from the area, something will seem amiss with one of the party members and all will remember the stories of the warlock's thousand curses.
These magical boots empower the wearer with several abilities at once. Wondrous leaping, water-walking, and even flying! Yet the boots possess an insidious curse upon them as well. A deep and almost unfathomable (by others) feeling of listlessness, boredom, and even apathy affects the boots' wearer at all times whenever they are donned. Magic will not dispel the effects.
And so while the wearer of the boots can perform great feats of action during combat or at other opportune times and key moments, they'll never really want to do so, complaining "Meh, what's the point of it all anyway?" or "I would fly up and save us all guys, but sigh, maybe uhm, soonish, mkay? Bit bored by this whole burning tower at the moment."
Naturally the boots wearer's fellow PCs will grow quickly frustrated with this arrangement. There have been numerous occasions when one angry PC literally tears off the boots from his companion's feet in anger, and dons them in turn, only to immediately suffer from the same effects.
The solution lies in constantly "motivating" the boots' wearer with successful rolls, involving threats, flattery, fiery speeches, or even bribery.