I kept checking on intercepts as a precaution, watching my back while focused on the crucial task of trying to figure out what Eric was really up to. One approach came to mind that hadn’t occurred to me before. I called the Switching Control Center that managed the switch providing Eric’s telephone service and convinced the tech to perform a line-history block, or LHB, a way of getting a report on the last phone number dialed from a phone line served by a 1A ESS switch.