‘Who’s that?’

’My name’s Champnell.  Has a message been received from me from the Limehouse Police Station?’

‘Step this way.’

We stepped that way,—­into a snug enough office, of which one of the railway inspectors was apparently in charge.  He was a big man, with a fair beard.  He looked me up and down, as if doubtfully.  Lessingham he recognised at once.  He took off his cap to him.

‘Mr Lessingham, I believe?’

’I am Mr Lessingham.  Have you any news for me?

I fancy, by his looks,—­that the official was struck by the pallor of the speaker’s face,—­and by his tremulous voice.

’I am instructed to give certain information to a Mr Augustus Champnell.’

‘I am Mr Champnell.  What’s your information?’

’With reference to the Arab about whom you have been making inquiries.  A foreigner, dressed like an Arab, with a great bundle on his head, took two single thirds for Hull by the midnight express.’

‘Was he alone?’

’It is believed that he was accompanied by a young man of very disreputable appearance.  They were not together at the booking-office, but they had been seen together previously.  A minute or so after the Arab had entered the train this young man got into the same compartment—­they were in the front waggon.’

‘Why were they not detained?’

’We had no authority to detain them, nor any reason, until your message was received a few minutes ago we at this station were not aware that inquiries were being made for them.’

‘You say he booked to Hull,—­does the train run through to Hull?’

’No—­it doesn’t go to Hull at all.  Part of it’s the Liverpool and Manchester Express, and part of it’s for Carlisle.  It divides at Derby.  The man you’re looking for will change either at Sheffield or at Cudworth Junction and go on to Hull by the first train in the morning.  There’s a local service.’

I looked at my watch.

’You say the train left at midnight.  It’s now nearly five-and-twenty past.  Where’s it now?’

‘Nearing St Albans, it’s due there 12.35.’

‘Would there be time for a wire to reach St Albans?’

’Hardly,—­and anyhow there’ll only be enough railway officials about the place to receive and despatch the train.  They’ll be fully occupied with their ordinary duties.  There won’t be time to get the police there.’

’You could wire to St Albans to inquire if they were still in the train?’

’That could be done,—­certainly.  I’ll have it done at once if you like.

‘Then where’s the next stoppage?’

’Well, they’re at Luton at 12.51.  But that’s another case of St Albans.  You see there won’t be much more than twenty minutes by the time you’ve got your wire off, and I don’t expect there’ll be many people awake at Luton.  At these country places sometimes there’s a policeman hanging about the station to see the express go through, but, on the other hand, very often there isn’t, and if there isn’t, probably at this time of night it’ll take a good bit of time to get the police on the premises.  I tell you what I should advise.’