Arlight.  For the sake of drama we're going to have the hipogriff caught in the building, although the spears can be pulled out of the way.<br/><br/>Pulling out each spear is a DC 12 strength check, +3 DC for each additional spear you want to pull out, so pulling out all six spears with a mighy heave or crash is a DC 27 strength check.  The spears have normal hardness and hit points, though they're made of iron.<br/><br/>Naturally, getting through the walls of force is a matter of dispelling them.<br/><br/>Finally, to Mark's senses, the Ambassador just picked up a moderate telepathy effect.