The Nasgareth may look like elves, but instead were created by an entirely different divine being, which admired the elvish looks and traits, but wanted to create his own army instead. One without Love.
The characters are given the task of transporting a flask of highly volatile liquid a long distance. The flask cannot be shaken too much or it will explode. The adventure involves stormy sea-voyages, bumpy cart rides through densely populated towns and horseback combat. In short there are many opportunities for it to break and explode.