In 2318, Grawla loyal to the Mountain Warlords would seek to displace the Humans on the Planet Hawking by using nuclear weapons to re-route a river through the city of New Cambridge causing dozens of fatalities and hundreds of injuries.

The Mountain Warlords had been uniting smaller warlord groups in the mountainous regions east of New Cambridge for decades. Though they occupied 'the mountains' they were fairly poorly equipped as they did not have access to the lower Cave-Grawla that were under the mountains. Similarly, they were far less capable than the River-City Grawla who occupied territory around the Human city of New Cambridge and the large river to the North of the city.

Expanding their power base became a matter of appealing to anti-human sentiment. The River-City clans maintained the position that the Humans were their slaves, though the truth of the matter was that a more mutually beneficial relationship had been established between the Humans and the River City Grawla. This made the River-City Grawla unwilling to outright attack the humans, and made them easy scapegoats for problems whenever the Mountain-Grawla wanted to stir up trouble.

The Mountain Grawla, having no way to attack the city directly, would instead use explosives to re-route a major river into New Cambridge. This would be used as a major recruiting tool among other clans that had yet to make up their mind about how to handle the Human situation.

The Humans would end up using the city's defensive systems to blast the river into taking a new direction away from the city, though by this point much of the damage had already been done. The city was designed to withstand a large number of varied attacks, however "Send a river at it" was not on the city planning and would lead to a redesign of some of the ground-level city defenses.

The Humans also decided not to risk overt retaliation against the Grawla, for fear of uniting the Grawla against them.