Solutions for Act II Scene 3 - Property

The format of this puzzle appears to be of a Venn diagram, which is further supported by the fact the puzzle's title is Property (all the elements in any one circle of a Venn diagram have the same property). It follows that we want to identify the central object, signified by a question mark.

Most if not all the objects should be immediately identifiable, however each circle does not seem to contain objects of any obvious physical similarities. The trick here is to spot that each picture has a common name that has exactly five letters, suggesting that the property each circle determines might be related to the names of the objects as opposed to the objects themselves. Replacing each image with its name, then, we get the following:

It is immediately obvious that each of the outer three circles contains words starting with a common letter, specifically K, S, and F (going clockwise from top-left). The three inner circles' rules are a little harder to identify, but should still become clear once considering that not only should each word within each circle obey its rule, but also all objects outside it must not satisfy the rule. This leads to the discovery of the inner circles' rules - respectively (going clockwise from the top) we have starts and ends with the same letter, contains exactly one vowel, and can be written in upper-case form with only straight lines, viz:

It follows that the solution must be a five-letter word made up of only straight lines, containing exactly one vowel, and starting and ending with the same letter (which cannot be K, S, or F). This gives the limited alphabet of {A,E,F,H,I,K,L,M,N,T,V,W,X,Y,Z} to choose from, and from this it is apparent the only vowel in the missing word must be the middle letter, since there are no plausible consonant blends of more than two letters available from this set (here Y is considered to be either a vowel or consonant depending on how it is pronounced in the word, however this interpretation is not important for determining the final answer).

Furthermore the two-consonant blends on either side of this vowel are similarly restricted, with the only really versatile start/end letter being T. It should eventually become clear that the only proper, common word that fits in the central section is THEFT, which also ties in with the title (we have found the "lost property").

The answer is: theft