Humphrey and the team face one of their strangest cases yet when a dead man is found in the centre of a crop circle. No-one knows who he is or how he got there. Conspiracy theorists suggest aliens are to blame, which seems possible when footage emerges of mysterious lights hovering above the field, but pragmatist Esther is sure that the answer lies closer to home. Brother and sister Andrew and Cassie Parker own North Farm, where the body was found. Do they know more than they're letting on? When the investigation leads the team to the site of an illegal rave, they're reunited with a familiar face who just might be the key to cracking the case wide open.Meanwhile, Martha faces her own professional challenge as her café is visited by a food critic. With Archie's help, she rises to the occasion, but in doing so, misses an important IVF appointment with Humphrey. Given pause for thought, she starts to question what she really wants. Archie, however, misreads Martha's uncertainty for something else, which has unforeseen consequences.