The Thin Red Line

Gydney and Kloyd, two tourists from Pluto City, stopped off in Boston before the whole kidnapping-of-MIT thing, and now we've lost contact with them. (Gydney's the one in the hat. Or maybe Kloyd is. In any event, which is which doesn't matter much to Plutonians.) Cross-universe transmission rates being what they are, the two tourists could only get three letters through from each destination point. They're clearly trying to send a message, but what?