The player carries a gizmo that is able to record actions performed by the player, then force him to repeat them when the gizmo is dropped. This includes storing actions that apply to topics, as in "look up anteater colonies in the guide".

"Anteaters"
A book is a kind of thing. Understand "book" as a book. A book has a table name called the contents.
Report consulting a book about:
   say "You flip through [the noun], but find no reference to [the topic understood]." instead.
Instead of consulting a book about a topic listed in the contents of the noun:
   say "[reply entry][paragraph break]".
The Guide to Desert Fauna is a book. The contents of the Guide is the Table of Critters.
Table of Critters
topicreply
"spines""You flip through the Guide for a while and eventually realise that spines are flora, not fauna."
"anteater colonies""The giant anteater, which grows to six feet in size and can kill a jaguar, is a solitary animal, found in many habitats, including grasslands, deciduous forests and rainforests. It does not form colonies. That's ants. They're actually quite easy to tell apart."
Death Valley is a room. The Guide is in the Valley.
The gizmo is in Death Valley. The gizmo has an action called idea. The description of the gizmo is "The gizmo is hard to describe, but it projects an idea of [idea]."
Before when the player carries the gizmo and the idea of the gizmo is waiting:
   say "[The gizmo] eagerly soaks up the whole idea of [the current action].";
   now the idea of the gizmo is the current action.
After dropping the gizmo:
   say "The percussion of the fall seems to have shaken the gizmo's idea loose! There's nothing for it now but [idea of the gizmo].";
   try the idea of the gizmo;
   now the idea of the gizmo is waiting.
Test me with "get guide / look up spines in guide / x gizmo / get gizmo / i / x gizmo / drop gizmo / get gizmo / look up anteater colonies in guide / x gizmo / drop gizmo".
Test me with "get guide / look up spines in guide / x gizmo / get gizmo / i / x gizmo / drop gizmo / get gizmo / look up anteater colonies in guide / x gizmo / drop gizmo".
Death Valley
You can see a Guide to Desert Fauna and a gizmo here.

>(Testing.)

>[1] get guide
Taken.

>[2] look up spines in guide
You flip through the Guide for a while and eventually realise that spines are flora, not fauna.

>[3] x gizmo
The gizmo is hard to describe, but it projects an idea of waiting.

>[4] get gizmo
Taken.

>[5] i
The gizmo eagerly soaks up the whole idea of taking inventory.

You are carrying:
a gizmo
a Guide to Desert Fauna

>[6] x gizmo
The gizmo is hard to describe, but it projects an idea of taking inventory.

>[7] drop gizmo
The percussion of the fall seems to have shaken the gizmo's idea loose! There's nothing for it now but taking inventory.

You are carrying:
a Guide to Desert Fauna

>[8] get gizmo
Taken.

>[9] look up anteater colonies in guide
The gizmo eagerly soaks up the whole idea of consulting the Guide to Desert Fauna about "anteater colonies".

The giant anteater, which grows to six feet in size and can kill a jaguar, is a solitary animal, found in many habitats, including grasslands, deciduous forests and rainforests. It does not form colonies. That's ants. They're actually quite easy to tell apart.

>[10] x gizmo
The gizmo is hard to describe, but it projects an idea of consulting the Guide to Desert Fauna about "anteater colonies".

>[11] drop gizmo
The percussion of the fall seems to have shaken the gizmo's idea loose! There's nothing for it now but consulting the Guide to Desert Fauna about "anteater colonies".

The giant anteater, which grows to six feet in size and can kill a jaguar, is a solitary animal, found in many habitats, including grasslands, deciduous forests and rainforests. It does not form colonies. That's ants. They're actually quite easy to tell apart.