The RAC traytop was off-loading my wife’s disabled Colt last night. It was behind the church, where she usually parks the car. The tray had just lowered the vehicle, when some loud shouts made us look up. Torch lights were bobbing towards us from the road reserve. Behind the lights loomed two characters, running full pelt toward us, shouting. We braced ourselves, not knowing what to expect – and they ran grunting straight past us – faces red, perspiring freely on this cold winters’ evening. They were in athletic singlets and shorts.

“You can’t get through that way” I shouted.

“This is private property!” my bride murmured.

No response – except about eight more characters, similarly attired, wheezed past us. Seeing our bemused faces, one cried out “Call the police!”
Now I was confused – were they chasing someone? There had been a burglary across the road earlier that day. Was he just having a lend of me? Why were they all dressed in athletics? 
One called out “Found it!”

They turned and ran off in the direction they had come, disappearing into the dark. Who were these people?…

… next morning I found these chalk marks on the ground, leading me to pose several hypotheses

1. They are alien markings, and our intruders are extraterrestrials in search of their lost space craft.
2. They are portals to a secret chamber where stolen goods are secreted and this was a raid by undercover police disguised as athletes.
3. They are markers for a local orienteering club out on a practice run.

Maybe, you, dear reader, can cast a light on this mystery. Or you may have an additional hypothesis as to what was really going on here. Feel free to share.