Instead, it would be other publishers who would revisit both scenarios in the twenty-first century. So Kenzer & Company first published B1 Quest for the Unknown, a version of B1 In Search of the Unknown for use with HackMaster, Fourth Edition, and would follow it up with not one, but two versions of B2 Keep on the Borderlands. First with B2 Little Keep on the Borderlands: An Introductory Module for Characters Level 1–4 in 2002, and then again in 2009 with Frandor’s Keep: An immersive setting for adventure. Another publisher to revisit B2 Keep on the Borderlands was Chris Gonnerman, with JN1 The Chaotic Caves, a scenario written for the Basic Fantasy Role-Playing Game. In addition, Faster Monkey Games published its own homage to B1 In Search for the Unknown with The Hidden Serpent, whilst Pacesetter Games & Simulations has published a number of extra encounters and sequels for both scenarios, most notably B1 Legacy of the Unknown and B2.5 Blizzard on the Borderland.
Yet Wizards of the Coast did not ignore its extensive back catalogue. It would release numerous titles in PDF, and even allow Print on Demand reprints, including both B1 In Search of the Unknown and ;B2 Keep on the Borderlands. Further, in 2017, it published Tales from the Yawning Portal, a collection of scenarios that had originally been published for previous editions of Dungeons & Dragons, including Advanced Dungeons & Dragons, First Edition, Dungeons & Dragons, Third Edition, and even D&D Next. These scenarios though, did not include either B1 In Search of the Unknown or B2 Keep on the Borderlands. Which upon first glance seemed a strange omission, but then came the announcement from Goodman Games about Original Adventures Reincarnated #1: Into the Borderlands.
Keep on the Borderlands: The Expansion is basic, perhaps too basic. It has three major problems. The first is is the lack of description and flavour and detail. The second is the fact that Palthos, the son of the Castellan of the keep, is mentioned at the beginning of the scenario and never mentioned again, and arguably, his disappearance and the potential reward for his return are the major hook for the Player Characters. This is a major omission. However, neither problem is insurmountable and with some effort upon the part of the Dungeon Master, better descriptions can be added to the scenario’s dungeon and the location where Palthos is being held prisoner can be decided upon. The third is the lack of description of the region beyond that described in B2 Keep in the Borderlands bar the mention and location of the bandit camp. Again, it is left up to the Dungeon Master to not only describe, but actually develop.