WATCH ONLINE, MOBILE, FREEVIEW 63, SKY 164, FREESAT 162 AND VIRGIN 216
Unknown objects, weird lights and a shocking criminal investigation - check out Scotland's Livingston UFO, Norway's Hessdalen lights and Portugal's Castelo de Bode Dam encounter. (S1, ep 1)
Strange lights, a government cover-up and something odd above the woods - experts revisit the Swedish Mora UFO photos, Mussolini's UFO files and the Rendlesham forest incident. (S1, ep 2)
An Air France pilot sees a huge object over Paris, UFOs are spotted over a quiet town in Portugal, and lone drivers in Denmark experience something rather strange... (S1, ep 3)
Witnesses are baffled as strange flying objects start appearing over Europe. Everywhere from Portugal to Romania, big questions are left unanswered. (S1, ep 4)
Witnesses reveal the story of a strange phenomenon in a remote Italian village. Strange objects are spotted over Sweden and a UFO is reported in Portugal. (S1, ep 5)
More strange stories come under the spotlight, including that of a disappearing US pilot, strange incidents in a Sicilian fishing village and a weird encounter over Germany. (S1, ep 6)
Experts investigate more strange sightings, including a silver missile travelling too quickly for pilots to pursue, and mysterious lights seen by thousands over Belgium. (S1, ep 7)