Earth and fire admire and exasperate each other: fire wants it now, earth wants it right. Used well, fire brings the push and earth makes it real — a formidable team. Otherwise you feel like brake and chaos to each other.
One initiates (cardinal), the other sustains (fixed): done well, it's the formula for projects that start AND finish. Done badly, one pushes change and the other digs in. Negotiation is this bond's muscle.