A Doomed Pilgrim in the Ruins of the Future

The Spiders stop as you approach the portal. They shy away, hissing and stamping their many legs against the sand. At first you believe it's the portal, but a deep rumble and the sudden shift of sand proves you wrong. An enormous sand worm bursts forth from the ground behind the portal. It stretches upwards into the sky, its enormous maw issuing forth a terrifying roar. The sand below your feet shifts knocking you to the ground and pulling you as it rushes to fill the space the worm once occupied. You are now being pulled closer to the portal, but the Worm is bearing down on you, It's tail may be trapped deep in the sand rendering it stationary, but you are definitely within its attack range now. And the spiders are going absolutely crazy, you may be able to sneak past them while they are distracted by the worm, but with the flailing and the gnashing of mandibles you don't fancy your chances.