The story starts with Frodo: a young hobbit, quite bright, a bit dissatisfied with what he's learnt so far and with his mates back home who just seem to want to get jobs and settle down and drink beer. He's also very much in awe of his tutor and mentor, the very senior professor Gandalf, so when Gandalf suggests he take on a short project for him (carrying the Ring to Rivendell), he agrees.

Frodo very quickly encounters the shadowy forces of fear and despair which will haunt the rest of his journey and leave permanent scars on his psyche, but he also makes some useful friends. In particular, he spends an evening down at the pub with Aragorn, who has been wandering the world for many years as Gandalf's postdoc and becomes his adviser when Gandalf isn't around.

After Frodo has completed his first project, Gandalf (along with head of department Elrond) proposes that the work should be extended. He assembles a large research group, including visiting students Gimli and Legolas, the foreign postdoc Boromir, and several of Frodo's own friends from his undergraduate days. Frodo agrees to tackle this larger project, though he has mixed feelings about it. ("'I will take the Ring', he said, 'although I do not know the way.'")

Very rapidly, things go wrong. First, Gandalf disappears and has no more interaction with Frodo until everything is over. (Frodo assumes his supervisor is dead: in fact, he's simply found a more interesting topic and is working on that instead.) At his first international conference in Lorien, Frodo is cross-questioned terrifyingly by Galadriel, and betrayed by Boromir, who is anxious to get the credit for the work himself. Frodo cuts himself off from the rest of his team: from now on, he will only discuss his work with Sam, an old friend who doesn't really understand what it's all about, but in any case is prepared to give Frodo credit for being rather cleverer than he is. Then he sets out towards Mordor.

The last and darkest period of Frodo's journey clearly represents the writing-up stage, as he struggles towards Mount Doom (submission), finding his burden growing heavier and heavier yet more and more a part of himself; more and more terrified of failure; plagued by the figure of Gollum, the student who carried the Ring before him but never wrote up and still hangs around as a burnt-out, jealous shadow; talking less and less even to Sam. When he submits the Ring to the fire, it is in desperate confusion rather than with confidence, and for a while the world seems empty.

Eventually it is over: the Ring is gone, everyone congratulates him, and for a few days he can convince himself that his troubles are over. But there is one more obstacle to overcome: months later, back in the Shire, he must confront the external examiner Saruman, an old enemy of Gandalf, who seeks to humiliate and destroy his rival's protege. With the help of his friends and colleagues, Frodo passes through this ordeal, but discovers at the end that victory has no value left for him. While his friends return to settling down and finding jobs and starting families, Frodo remains in limbo; finally, along with Gandalf, Elrond and many others, he joins the brain drain across the Western ocean to the new land beyond.