The Pulsar research station lay on the border of the Orion Nebula, where regular trade routes ended and true unknown space began. It was late in the day when Nela, the chief engineer, was peering through an armoured window at the ice shards slowly circling the station. Behind her, in the control room, Olek was checking the quantum log entries. There were only six people working on Pulsar - everyone was here for a different reason: Nela was looking for a challenge, Olek was to get away from Earth, Dr Qiang was researching exotic particles, and twins Zoe and Zara were managing the vital systems. The youngest was Marek, a brilliant programmer who sometimes talked to himself on the radio. This evening something was different. Working in silence, the whole crew could sense the tension. Suddenly, a strange pulsating sign appeared on the monitor - a sequence of rapidly changing sequences of numbers. - Did you check it, Olek? - asked Nela, moving over to the console. - I have no idea what it is. I've never seen such transmission parameters,' replied the boy, wrinkling his eyebrows. Marek seized the file and threw himself into decoding. His fingers danced across the keyboard, lines of code began to appear on the screen that shouldn't have been there at all - no one on the station had installed such software. Zoe and Zara looked at each other communicatively. - Where is the source of the signal? - Zara asked, trying to bring up the location map. Marek looked at the data. - He... it's coming from the station's outer shell. Like something, or someone, is broadcasting it from our own shell.... At the same instant, a bang sounded in the distant corridor. Lights flickered, red alerts went off in alarm. The entire crew sprang to their feet. A cold, metallic sound they had never heard before spread across the station. Nela grabbed the torch and nodded to the rest: - We have to check it out. Together. They set off, hearts beating hard, ready to discover what this unusual transmission was....