It’s the juxtapositions that get you. A hot morning commute after the warmest May bank holiday on record, and the Central Line is sweltering. Opposite me is one of those women who is so striking you need to keep reminding yourself not to look too long to avoid creepiness. But it’s honestly hard to look away. She’s straight off a science fiction movie; pale skin, long black hair that is Japanese-straight, wearing tweed pattern linen trousers against the heat and a pale blue T-shirt with a pixelated picture of a glamorous black woman whose face is haloed by an enormous Afro. She has fine features that seem almost unnaturally symmetrical. But what’s really remarkable is her make up. Her small mouth is outlined in a metallic bronzy red. She has red eye shadow on her upper lids and black and grey eyeliner below. And around her eyes she has dabbed a pale gold blusher that comes down over the top of her wide cheekbones. She also has a smudge of gold on the tip of her nose; I resist the urge to lean over, tap her knee and ask if it’s deliberate. It would break the spell.
Two seats down is a tall middle-aged man, receding silver hair close-cropped to an iron fuzz and a neat salt-and-pepper beard with the pepper descending from both corners of his mouth. He wears angular metal frame glasses, of the type favoured by trendy architects. But he definitely isn’t an architect. I noticed before he sat down that he was wearing the full-length black cassock of a Catholic priest; immaculately pressed with every pleat in the skirt in place. A column of shining black buttons descends from the neat white rectangle of his dog collar. The immaculate look is spoiled only slightly by the yellow and black striped pencil clamped in the left-hand corner of his mouth, which he removes occasionally to make notes in the book he’s intently studying. Titled “The Mystery of the Eucharist”, it has the most bizarre cover styling I have ever seen: shocking pink, with the title in scrolling white calligraphy of the sort that would be more at home on a 1970s soft porn novel. Whatever the mysteries are, they are more enthralling than the figure from the future seated a few metres to his right, but then he’s made a vow about that.

It takes a certain amount of panache to wear a bowler hat. In these days where not many men wear hats at all, the formal styles are approaching extinction. And the bowler, with its connotations of finance and upper-class twittery most of all.
That hasn’t put this chap off.
The hat is sat very squarely on his head. It’s a slightly archaic style, with the brim rolled up on itself at the sides and projecting out straight to the front and back. It’s also not a typical colour; not a banker’s bowler in black, or a countrymen’s or rider’s protective headgear in brown, but an ash-grey affair with a paler dove grey band and binding around the edge of the brim.
The head it is sat on is middle-aged, distinguished and black. A black man in a bowler is remarkable indeed, and the wearer exudes the confidence to carry it off. It’s difficult to gauge his age; most of his hair – if he has hair – is covered, and the few inches exposed above his neck are cropped short, starting to grow back in iron-grey peppercorns. He looks focused and businesslike, attentive but not glancing around, intent on his own business in his business hat.
You can look at some black men and see their origins in the slant of cheekbones, the set of the eyes, the line of the chin and the dome of the forehead. The narrow, gracile bone structure of the Maasai, the broad strength of the Nubians. I can’t see that here, which although he is silent this makes me think he might be Caribbean; a mixture of African lineages, transplanted to the Americas.
I can see sensible, narrow-cut dark trousers and well-worn but sturdy brown lace up Oxford shoes, but the rest of his outfit is hidden under a voluminous kneelength raincoat: the type that can only be called a Mac. It’s a venerable garment, creased through years of wear, fading along the creases and shapeless, hanging from his shoulders like a bell. It’s fawn in colour, toning with the trim on the bowler although from the look of him, coordination was hardly a factor in getting dressed. This is all about utility.
His body language is just as notable as his outfit. He is standing by the double doors in the Tube carriage; feet firmly planted in a stance like a tai chi practitioner or a boxer: one foot facing forward, the other set at a slight angle. His knees are slightly flexed, and I can see the tension transferring his weight from the front foot to back foot through the tendons in his thighs. He’s surfing the train, keeping his balance against its lurches and shudders. He isn’t even holding on to a handrail: his right hand is pressed, tense but open, against the rail, which runs down his index finger, down his palm and to the heel of his hand. He keeps his upper body balanced by pressing and relaxing against the bar. And these compensations keep the bowler and static as the head of a hunting raptor as it quarters the fields below for its prey.
And he remains impassive. His eyes flicker across the platform as the train doors open, but don’t light on anybody or anything, giving the impression of seeing everything he needs to see. The expression does not change, the lips do not part, the eyebrows do not shift. As the crowd surges on, he turns to face down the carriage, keeping the hand pressed against the rail, now pointing with the fingers down, the feet shifting to a new sure anchorage.
It’s only when he crosses the carriage to get off at Holborn that I realise who and what he must be and where he is going. Russell Square is nearby, and as all readers of Ben Aaronovitch’s novels know, this is the address of the Folly, the 19th-century pile that is the headquarters of the followers of the more esoteric studies of Sir Isaac Newton; the Newtonian practioners; the Isaacs; the wizards. That Mac is concealing a long poacher’s pocket in its lining, containing a twisted steel pole at the core of an oaken staff that stores his power. The wizards help uphold the Queen’s peace; they used to be Army but are members of the Metropolitan Police, the few survivors of an apocalyptic battle in the forests of Germany in the 1940s. Since then, some survivors have been ageing backwards, so there is no way of knowing how old this gent might be. But he is surely on the way to a debriefing session with his superior officer, DCI Thomas Nightingale. Officially, Nightingale would be his Master, but he is a gentleman, a Mensch and a Tzadik. Sensitive to the connotations of the title Master, he is quite happy to be called Guv.