In spite of the testimony of my own feelings, the miseries of Clithero appeared in some degree, phantastic and groundless. A thousand conceivable motives might induce him to pervert or conceal the truth. If he were thoroughly known, his character might assume a new appearance, and what is now so difficult to reconcile to common maxims, might prove perfectly consistent with them. I desire to restore him to peace, but a thorough knowledge of his actions is necessary, both to shew that he is worthy of compassion, and to suggest the best means of extirpating his error. It was possible that this box contained the means of this knowledge. (740)

The saga of Clithero's boxes and the manuscript hidden inside begins on page 739 of Edgar Huntly when Edgar and the Inglefield's housekeeper "converse an hour" before Edgar's planned midnight dig. Edgar's subsequent return to his room - formerly occupied by Clithero - revives interest in a "square box" which the housekeeper identified as the only possession that Clithero left behind. Edgar's description of this container allows the reader to examine its symbolic purpose:

I inquired what this man [Clithero] has left behind, and found that it consisted of a square box, put together by himself with uncommon strength, but of rugged workmanship. (739)

[...]

I lifted it and found its weight by no means extraordinary. Its structure was remarkable. It consisted of six sides, square and of similar dimensions. These were joined, not by mortice and tennon; not by nails, not by hinges, but the junction was accurate. The means by which they were made to cohere were invisible. [New paragraph] Appearances on every side were uniform, nor were there any marks by which the lid was distinguishable from its other surfaces. (739)

And then in the next chapter, as Huntly tries to open the box, he describes the process:

All its parts appeared equally solid and smooth. It could not be doubted that one of its sides served the purpose of a lid, and was possible to be raised. Mere strength could not be applied to raise it, because there was no projecture which might be firmly held by the hand. (742)

Edgar succeeds in opening the box; however, the opening of the box irreparably damages its structure.

I now perceived that Clithero had provided not only against the opening of his cabinet, but likewise against the possibility of concealing that it had been opened. (742)

Unfazed, Edgar proceeds with his dig and retrives another box that "was equally inaccessible with the other" (744). In this box he finds a manuscript which "essentially agreed with that which had been told by Clithero" (745).

The manuscript itself functions as an embedded narrative, but instead of telling a story, it seemingly confirms a story. The presence of two identical boxes, one of which contains an apparently crucial manuscript to the novel while the other, though equally obscured, is empty, is a metaphor for the attempt at interpretation of the Gothic. As Robert Hume proposes in his essay "Gothic versus Romantic: A Revaluation of the Gothic Novel," "the writers of Gothic never offer intuitive solutions" (289). Two identical boxes which contain wildly different narrative phenomena is a perfect example of the uncertainly which pervades the "insides" of Edgar Huntly.