The first person upon whom suspicion rested was the Swedish housemaid, Bertha Lund. But it did not linger long, or with more than a moth-like pressure, on that robust and straightforward individual. Her story, thrice repeated in response to questions by the marshal, Chief Federhen, Inspector McCausland and the district attorney, had not varied a hair, although each time new details were added, as the questions of the different examiners opened new aspects of the affair.
"Prime proof of her honesty," said McCausland. "The rote story shrinks and varies, but never expands."
So the only fruit yielded by the ordeal which Bertha underwent was a thorough description of the house and household, pieced together from her replies, and McCausland had soon left her far behind in his search for a tenable theory.
The cook, Ellen Greeley, had not yet made her appearance. Bertha professed to have seen her dressing herself in her chamber and gave a clear description of her clothing, for the benefit of McCausland's note-book—green plaid skirt, brown waist, straw hat with red, purple and yellow pompons. Ellen was dressing "uncommonly rich" of late, they said. Bertha had talked with her upstairs and had heard the back door slam about the time when Ellen might be supposed to be departing. It had been the cook's holiday afternoon, and she was going to run over to her sister's, as she generally did, and return for supper, leaving Bertha to keep house.
But her sister had not seen her and she had not returned. A slow, heavy girl, rather apt to take the color of her mood from those around her, she seemed a creature who might be influenced to wrongdoing, but hardly the one to instigate it. So far as could be learned, the plain truth was romantic enough for Ellen Greeley, and she was not accustomed to embellish it with flowers of her own imagination. Nevertheless, after exhausting this subject, McCausland checked her name with the mental note "an accomplice, if anything," and the woman's prolonged absence, together with those "uncommonly rich" dresses she wore of late, the more he dwelt on them, prompted him the more to erase the modifying clause and let his mental comment stand "an accomplice."
But of whom? Ellen's sister and Bertha had both mentioned one Dennis Mungovan, the cook's sweetheart, who, until three weeks ago, had been coachman at the Arnold's. Some repartee, or insolence, when reprimanded for smoking (he was described as a tonguey lout) had provoked his discharge and he had been heard to threaten vengeance behind the professor's back, though at the time his words were muttered they were ignored as a braggart's empty vaporing. Twice he had called to see Ellen at the house, but he had not shown his face since the week before the professor died; and even at his favorite haunt, a certain Charles street stable, all trace of him had been lost. As he was a resident of this country for less than a year he may have crossed the water again to his home, but if this were so Bertha felt sure Ellen would have manifested her lonesomeness. "She had a great heart to the man," said the Swedish housemaid.
"Well, what have you collected against him?" said the district attorney, to whom McCausland had just been exhibiting these results of his investigation. They were alone, save for a bloodhound, in the inspector's office at police headquarters.
"Opportunity, motive and circumstances. I don't rule out the other two as accessories, you understand." The "other two" were Mungovan and Ellen Greeley, who with Robert had been arranged in a triangle by the detective.
"That remains to be fitted into the developments, I presume?"
"First, as to circumstances. The young man turns up about 11 o'clock at a fire which started at 3:30, which destroyed his own home, and which was advertised all over the country within a radius of thirty miles before sunset."