Calatrava had won the commission to rebuild the transport interchange at the World Trade Center. A skein of subway lines passes beneath the site. It seemed incidental to the main unfolding twin dramas of the story, namely: would Libeskind be able to hang onto the spirit of his masterplan, culminating in his 1776-foot tall "Freedom Tower"? And would the subsequent competition to design a ground-level memorial to the tragedy produce a sufficiently dignified and timeless winner? As these sagas ground relentlessly on, nobody thought too much about the rail station, even if it alone is worth two billion dollars. Then Calatrava stepped forward, blinking owlishly, and produced the design of his lifetime. A great asymmetrical winged building in glass and steel, right in the plaza of the proposed redevelopment, providing shelter and focus, capable of sliding open to the sky.