A mullion sealing bridge and method for use in a curtain wall system. In one aspect, the bridge is placed at an intersection horizontal and vertical mullions to divert fluid along the curtain wall system. This Abstract is provided to comply with rules requiring an Abstract that allows a searcher or other reader to quickly ascertain subject matter of the technical disclosure. This Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.