Missing signal from Alpha Centauri

Lena sat at the panoramic window of the research vessel 'Explorer 2', gazing out at the endless sea of stars. Max, her younger brother, was hovering right next to her, trying at all costs to set the radio telescope to the latest secret signal. It was chilly - as chilly as it could be in space, where the sun of Alpha Centauri shone against a dark blue background. The siblings were not here for the fun of it. Their mum, a famous astrobiologist, had been given a special assignment by the Interplanetary Union of Explorers: to pick up and investigate a lost signal that had come all the way from the depths of the Alpha Centauri system. Her husband, a dad of children, piloted the ship, checking the course on board. Lena corrected the headphones on her ears. A quiet buzzing sounded in the ether - she was sure it was no coincidence. Every now and then, Max tossed her a notebook with strange symbols he'd been drawing since the morning, convinced they were messages from aliens. "Stop joking, Max," hissed Lena, but deep down she was just as excited. Suddenly, the signal changed. A short, metallic sound flew through the speakers and an unintelligible code appeared on the monitor. The ship spontaneously began to change course, as if something was attracting it. Lena looked terrified at Max - suddenly the lights on the ship began to flicker, and her parents' automated console displayed unfamiliar terms: "ENTRY TO ZONE X". As Lena tried to get the frantic keyboard under control, Max noticed a strangely glowing, unfamiliar structure approaching them through the window. Was it some kind of vehicle? Or maybe... a space station? Then the entire cabin flashed with a purple light, and unfamiliar translucent signs appeared around them, slowly swirling in the air. The ship stopped in absolute silence. Lenka and Max's parents tried to make contact, but communication with the control centre had disappeared. "What do we do now?" - whispered Max, squeezing his sister's hand. A mysterious door floated in front of them and slowly began to open....