The Vanished

People began going missing from the advance survey teams. The records were complete, the protocols were tight, and people vanished quietly off the roster.

The first was Daniel Vela, deputy leader of the second advance survey team, forty-seven years old, with an SOP compliance record of 100% over the past 4 years. Before setting out, every one of them had signed 3 lines: do not leave the group, do not sample alone, do not leave line of sight.

The whole of his walking away was recorded on the timestamps:

12:14  Kovac suit panel alert: team member D-04 more than 100 metres out of formation
12:57  Orbital scan, measured  800 metres north of the sampling point
13:11  Orbital scan, measured  1.2 kilometres north of the sampling point
13:48  Orbital scan            Thermal signature gone entirely (2.4 kilometres north)

He walked that stretch steadily. His average pace between 12:57 and 13:11 differed from his baseline speed before departure by less than 3%; the thermal imaging showed no sign of him running and no sign of him searching for anything. The 2 sent after him came back 5 minutes later and said he was already outside line of sight.

Tracking on the surface depended on the orbital scan, and the window was not open at all hours: once a pass finished, the next was more than ten minutes away. Position between windows could only be projected from pace, and a projected value could not stand as a measurement. So when a person walked away on the surface, what the command tower saw was a broken string of points, with a stretch of dataless time lying between each pair.

The vanishing of the thermal signature was the hardest item to explain. An EVA suit's thermal signature comes from the temperature of the suit itself and has nothing to do with whether a person is inside it; as long as the suit is powered there is a signature. The whole signature going missing meant the whole suit was outside the scan area. And the geological scan of that position showed crustal thickness 31 kilometres, no faulting, no known cavity of any kind. That phrase, "no known", was pressed once at the shift handover table, and what the man pressing wanted to hear was that the scan had blind spots.

Before he disappeared he opened his own personal emergency band, which only the wearer of a suit can open, broadcast five words, and shut the panel off:

There are sounds underground.

The disappearance on its own was unsettling enough. The question that kept the command tier awake was this: if there is something on this planet that can make a person disappear, then would it send a person back?