The Lost Portal is a short adventure for 4-5 characters between levels 1-5 by Glen Cooper.
Recently, a series of earthquakes that hit the area have allowed to monster to come to the surface and attack travelers and villagers. The characters are hired by an Elf to help him investigate the source of the monsters. Or that’s what he says.
The adventure is organized fairly well. The layout and the formatting are good. I believe the best feature is the sidebars which provide quick access to rules, possible treasure and other helpful information for the DM. That’s extra helpful since some uncommon rules are used, such as drowning. I should note here, however, that some more text editing is needed since there are a few errors but they don’t create any problems running the adventure.
As for the encounters, they seem fairly balanced. There are three versions for each of them depending on the level of the characters(levels 1, 3 or 5). A stat block for a modified monster is included in an appendix, but only the Monster Manual pages are provided for the rest of them.
Moreover, I really like how the maps have been handled in this adventure. Only one map is needed since the whole adventure takes place in one area, a cave. However, a top down and a side view version of the map are provided. Also, there are marked and unmarked versions of them as well as a printer friendly version of the unmarked one.
Finally, there’s some extra content that can be used by the DM. There’s an interesting idea on how to add tension and the sense of urgency into the adventure. Also, a way to use the Rory Story Cubes in order to generate NPCs is provided. Don’t worry if you do not own them, since there are some tables that you can use instead.
Ultimately, The Lost Portal is an interesting adventure that can be easily integrated in any campaign and ran by DMs of any level of experience. It can also be used as an introductory adventure, if you’re planning on running the Out of the Abyss campaign, which adds extra value to it.