’I never was there; I only made a guess, because the house I am interested in is a private asylum.’

‘Well, you guessed right.  What then?’

’You might reconnoitre the ground to-morrow—­the exits, there are sure to be some towards waste land or market gardens.’

‘Jolly!’ said Trevor.  ’I’ll make up as a wanderer from Suffolk, looking for a friend in the slums; semi-bargee kind of costume.’

‘That would do,’ said Merton.  ’But you had better go in the early morning.’

‘A nuisance.  Why?’

’Because, later, you will have to get a gang of fellows to be about the house the day after, when I pay my visit.’

‘Fellows of our own sort, or the police?’

’Neither.  I thought of fellows of our own sort.  They would talk and guess.’

‘Better get some of Ned Mahony’s gang?’ asked Trevor.

Mr. Mahony was an ex-pugilist, and a distinguished instructor in the art of self-defence.  He also was captain of a gang of ‘chuckers out.’

‘Yes,’ said Merton, ’that is my idea. They will guess, too; but when they know the place is a private lunatic asylum their hypothesis is obvious.’

‘They’ll think that a patient is to be rescued?’

’That will be their idea.  And the old trick is a good trick.  Cart of coals blocked in the gateway, or with another cart—­the bigger the better—­in the lane.  The men will dress accordingly.  Others will have stolen to the back and sides of the house; you will, in short, stop the earths after I enter.  Your brougham, after setting me down, will wait in Hammersmith Road, or whatever the road outside is.’

‘I may come?’ asked Trevor.

‘In command, as a coal carter.’

‘Hooray!’ said Trevor, ’and I’ll tell you what, I won’t reconnoitre as a bargee, but as a servant out of livery sent to look for a cat at the Home.  And I’ll mistake the asylum for the Home for Cats, and try to scout a little inside the gates.’

‘Capital,’ said Merton.  ’Then, later, I want you to go to a curiosity shop near the Museum’ (he mentioned the street), ’and look into the window.  You’ll see a little brown piece of wood like this.’  Merton sketched rapidly the piece of wood which Miss Markham wore under her dress.  ’The man has several.  Buy one about the size of a big cigar for me, and buy one or two other trifles first.’

‘The man knows me,’ said Trevor, ‘I have bought things from him.’

’Very good, but don’t buy it when any other customer is in the shop.  And, by the way, take Mrs. Lumley’s portmanteau—­the lock needs mending—­to Jones’s in Sloane Street to be repaired.  One thing more, I should like to add a few lines to that manuscript I gave you to keep in your safe.’

Trevor brought the sealed envelope.  Merton added a paragraph and resealed it.  Trevor locked it up again.

On the following day Trevor started early, did his scouting in Water Lane, and settled with Mr. Mahony about his gang of muscular young prize-fighters.  He also brought the native Australian curiosity, and sent Mrs. Lumley’s portmanteau to have the lock repaired.