Beginning with a short piece of atmospheric fiction and an explanation of what a beanstalk is, this is a set of adventure resources set on the planet Beta Canum Venaticorum-4 where the first beanstalk was erected. There's also material useful for use with plotlines that concern Earth's beanstalk, particularly useful if you have Rotten to the Core, although you don't need that to make use of this book.
The first chapter, The Stage, deals with the history, geography and current state of Beta Canum, useful whenever the party might choose to visit, or in devising reasons for them to go there. Like any frontier world in 2300AD, it is a series of contradictions, high tech rubbing shoulders with primitive - people either have the very best, most advanced, equipment for a particular job or they make do with what they can make for themselves. So a fishing village may boast boats crammed with high tech equipment to find and catch fish, but still use outhouses rather than indoors plumbing! Several nations are represented amongst Beta Canum's colonies, generally occupying their own continent. Whilst native plants and animals are inedible (indeed toxic) to humans, imported Earth flora and fauna have flourished and the planet is already exporting produce to other worlds.
Next is The Actors, a chapter jam-packed with relevant NPCs. Most will turn up if you use the adventures in this book (and are cross-referenced so you know where they'll show up, but may be of use elsewhere as well. Each has a detailed background which will help you bring them to life as rounded figures who have a full part to play in this alternate reality, not just cardboard cut-outs there to fill a single purpose and then be forgotten.
The following chapter, The Technical Data, provides loads of background as well as maps and charts, including a lot of detail on beanstalk construction and operation. There's even a handout in the form of a leaflet aimed at tourists newly-arrived on Beta Canum, excellent for setting the scene when the party first arrives.
Finally, The Drama contains three separate scenarios that you can run. Interestingly, this section starts by referring to the adventure The Tricolour's Shadow which was included in the original Traveller: 2300 box set, as the adventures here could be run following it (but you do not need to have played it to enjoy these adventures, fortunately!). These three adventures are all suited to 'troubleshooter' characters, and two at least involve riding the beanstalk, whilst the other includes rooting around its ground facility. All provide good, edge-of-the-seat fun, although those players who prefer to use combat to solve every situation will do less well than those who enjoy interaction and infiltration.
A brief Afterword has additional material about Beta Canum, and that's it. The adventures are good if acting as hired troubleshooters appeals to your group (although the last one could be run for any party who has occasion to ride the beanstalk at any time), and the other material provides you with yet another well-imagined planet to visit.