When Chris and Tyler are sent to Equestria through a magical door, they think it will be calm and peaceful, but what will happen when this doesn't turn out to be the case?

An ODST and his squad are sent through slipspace to a place known as Equestria. When another slipspace hole opens up, containing covenant dropships filled with the various species, will they be able to protect this planet from the monsters that were destroying their own?