SG-13 were surveying the planet P3X-666 and found ruins of Ancient origin. They were then attacked by a Reconnaissance probe, much like the Unmanned Aerial Vehicle in function. They destroyed the probe, but not before it had time to send out a subspace alert to the Goa'uld. Wells was injured in the attack and Dr. Janet Frasier was killed treating him though Wells survived thanks to her sacrifice. At an earlier time, they were surveying P2X-787 that they found similar to the above planet. (SG1: "Heroes, Part 1", "Heroes, Part 2")