To carry his plan into execution, he resolved on choosing the night of August 18-19, 1832. On this evening he sat drinking in a low tavern till 10 o'clock, when he left, returned to his lodgings, where he collected the tools he believed he would require, a candle and flint and steel, and then betook himself to the mausoleum.

In the first place, he found it necessary to climb over a wall of boards that encircled the portion of the grounds where was the mausoleum, and then, when he stood before the building, he found that to effect an entrance would take him more time and give him more work than he had anticipated.

The mausoleum was closed by an iron gate formed of strong bars eight feet high, radiating from a centre in a sort of semicircle and armed with sharp spikes. He found it impossible to open the lock, and he was therefore obliged to climb over the gate, regardless of the danger of tearing himself on the barbs. There was but a small space between the spikes and the arch of the entrance, but through this he managed to squeeze his way, and so reach the interior of the building, without doing himself any injury.

Here he found a double stout oaken door in the floor that gave access to the vault. The two valves were so closely dovetailed into one another and fitted so exactly, that he found the utmost difficulty in getting a tool between them. He tried his false keys in vain on the lock, and for a long time his efforts to prise the lock open with a lever were equally futile. At length by means of a wedge he succeeded in breaking a way through the junction of the doors, into which he could insert a bar, and then he heaved at one valve with all his might, throwing his weight on the lever. It took him fully an hour before he could break open the door. Midnight struck as the valve, grating on its hinges, was thrown back. But now a new and unexpected difficulty presented itself. There was no flight of steps descending into the vault, as he had anticipated, and he did not know the depth of the lower pavement from where he stooped, and he was afraid to light a candle and let it down to explore the distance.

But Stubenrauch was not a man to be dismayed by difficulties. He climbed back over the iron-spiked gates into the open air, and sought out a long and stout pole, with which to sound the depth, so as to know what measures he was to take to descend. Going into the Ducal orchard, he pulled up a pole to which a fruit tree was tied, and dragged it to the mausoleum, and with considerable difficulty got it through the gateway, which he again surmounted with caution and without injury to himself.

Then, leaning over the opening, holding the pole in both hands, he endeavoured to feel the depth of the vault. In so doing he lost his balance, and the weight of the pole dragged him down, and he fell between two coffins some twelve feet below the floor of the upper chamber. There he lay for some little while unconscious, stunned by his fall. When he came to himself, he sat up, felt about with his hands to ascertain where he was, and considered what next should be done.

Without a moment's thought as to how he was to escape from his position, about the possibility of which he was not in the smallest doubt, knowing as he did his own agility and readiness with expedients, he set to work to accomplish his undertaking. With composure Stubenrauch now struck a light and kindled the candle. When he had done this, he examined the interior of the vault, and the coffins he found there, so as to select the right one. Those of the Duchess Augusta and her husband the late Duke were very much alike, so much so that the ruffian had some difficulty in deciding which was the right one. He chose, however, correctly that which seemed freshest, and he tore off it the black cover. Under this he found the coffin very solid, fastened by two locks, which were so rusted that his tools would not turn in them. He had not his iron bar and other implements with him now; they were above on the floor of the upper chamber. With great difficulty he succeeded at length in breaking one of the hinges, and he was then able to snap the lower lock, whereas that at the top resisted all his efforts. However, the broken hinge and lock enabled him to lift the lid sufficiently for him to look inside. Now he hoped to be able to insert his hand, and remove all the jewellery he supposed was laid there with the dead lady. To his grievous disappointment he saw nothing save the fading remains of the Duchess, covered with a glimmering white mould, that seemed to him to be phosphorescent. The body was in black velvet, the white luminous hands crossed over the breast. Stubenrauch was not the man to feel either respect for the dead or fear of aught supernatural. With both hands he sustained the heavy lid of the coffin as he peered in, and the necessity for using both to support the weight prevented his profane hand from being laid on the remains of an august and pious princess. Stubenrauch did indeed try more than once to sustain the lid with one hand, that he might grope with the other for the treasures he fancied must be concealed there, but the moment he removed one hand the lid crashed down.

Disappointed in his expectations, Stubenrauch now replaced the cover, and began to consider how he might escape. But now—and now only—did he discover that it was not possible for him to get out of the vault into which he had fallen. The pole on which he had placed his confidence was too short to reach to the opening above. Every effort made by Stubenrauch to scramble out failed. He was caught in a trap—and what a trap! Nemesis had fallen on the ruffian at once, on the scene of his crime, and condemned him to betray himself.

Although now for the first time deadly fear came over him, as he afterward asserted, it was fear because he anticipated punishment from men, not any dread of the wrath of the spirits of those into whose domain he had entered. When he had convinced himself that escape was quite impossible, he submitted to the inevitable, lay down between the two coffins and tried to go to sleep; but, as he himself admitted, he was not able to sleep soundly.

Morning broke—it was Sunday, and a special festival at Coburg, for it was the twenty-fifth anniversary of the accession of the Duke, so that the town was in lively commotion, and park and palace were also in a stir.