Darkness was slowly settling on the campus of the Mage Academy in Green Forks. The grasses in the courtyard moved gently from the wind, and the smell of old parchment and sage lingered in the air. The tall, stone Astral Tower was almost empty - it was where the omni-champions kept the forbidden books and the most powerful artefacts. Lina, Alan and Frederick sat on the marble steps, glancing nervously at each other. The moonlight and excitement of the suddenly found map was reflected in their eyes. Last week, during a boring Spell Theory class, Alan had accidentally slipped a dusty old volume off the shelf. The book opened to a faded page with a drawing of a snake's head and unusual markings around it. For days they had been working out the clues in secret. Now they were sure - there was a mysterious portal beneath the Astral Tower, as told by an obscure academic legend. Under cover of darkness, they slipped out of the dormitory. Lina led the way, clutching in her hand a silver key she had found hidden behind a fate of stone under the tower steps. Frederick carried a glowing vial of the potion of light, and Alan carried a map and notes. They crept through corridors and past magical traps until they reached an inconspicuous door in the lowest level of the tower. They opened it cautiously. Behind them stretched a cool, dark corridor lined with black tiles that muffled any sound of footsteps. The further they walked, the thicker the fog became and the more they sensed the presence of something unnamed. At the end of the corridor, a massive gate laced with symbols waited. Rope touched its surface and suddenly the runes glowed with blue light. The door opened with a protracted creak, revealing a spiral staircase leading downwards. Strange whispers reached them at the bottom. Alan ran his fingers along the wall and suddenly heard a voice in his head whispering words from a legend: "Only those who know their own shadow will cross the Threshold of Illusion". They stood in front of a huge portal of black crystalline glass, whose surface shone like the night sky. Reflections of light moved to the rhythm of their breaths, and indistinct, rippling silhouettes began to form inside the portal. - 'Are you two ready? - whispered Lina, looking at her friends, feeling the tension building up. At that moment, everything around them trembled, and a distant, beckoning voice came from inside the portal....