"Exactly. Being here with Mrs. Middlemore's permission. You've got a lot to learn, Wigg, and one of the lessons I'd advise you to take to heart"--here he looked significantly at Mrs. Middlemore--"is not to poach on a pal's preserves." Constable Wigg may have felt the reproach, but he took no notice of it. "You may as well come to the door with me, Nightingale." "I've no objections." "I'll come too," said Mrs. Middlemore, nervously. "I wouldn't be left alone here for anythink you could orfer me." The three walked upstairs to the passage, Mrs. Middlemore needing the support of Constable Nightingale's arm round her waist; but the moment the fastenings of the street-door were unloosed, it flew open as though a battering ram had been applied to it, and the wind and snow swept in upon them with undiminished fury. "Hanged if it ain't getting worse and worse!" muttered Constable Nightingale, helping the others to shut the door, which was accomplished with great difficulty. "Don't make a noise in the passage," whispered Mrs. Middlemore to Constable Wigg. "Mr. Felix 'll 'ear it, and he'd never forgive me." "We'll take it for granted, then, that the alarm is given," said Constable Nightingale, "and we'll go downstairs, and consider what ought to be done." CHAPTER V. DR. LAMB TELLS THE CONSTABLES AND MRS. MIDDLEMORE WHAT IS THE MATTER WITH MR. FELIX. Arrived once more in that comfortable apartment, they shook off the snow dust which had blown in upon them from the street. Then Constable Nightingale assumed a judicial attitude. "In case of anything being wrong," he said, "we must all be agreed upon what has took place before it's discovered." "Before what's discovered?" cried Mrs. Middlemore. "That we've got to find out." "It's ten to one there's nothing to find out," said Constable Wigg. "It's ten to one there is," retorted Constable Nightingale. "I go a bit deeper than you, Wigg; but whether there is or there ain't, it's always well to be prepared with a story. I've got something in my mind that you don't seem to have in yours; what it is you shall hear presently. Mrs. Middlemore, going out for her supper-beer at her usual hour, about half-past eleven shuts the street-door behind her, and does not return till past twelve. Is that correct, ma'am?" "Quite correct, Mr. Nightingale; but what are you driving at?" "All in good time, my dear. You leave the house safe, and you are sure you shut the street-door tight?" "I'll take my oath of it." "It may come to that; I don't want to scare you, but it may come to that. When you come back with the supper-beer you find the street-door open?" "But I don't." "Excuse me, you do; it's necessary." "Oh!" "And I'll tell you why. When you come home you find Wigg and me here, don't you?" "Yes."