Enigma

Kharkov in the face of the renewed German offensive
    At ten to eight Mrs Armstrong came in with the morning post. Nothing for Mr Bonnyman ('thank God for that,' said Bonnyman), two letters for Miss Jobey, a postcard for Miss Quince, a bill from Heffers bookshop for Mr Noakes and nothing at all for Mr Jericho—oh, except this, which she'd found when she came down and which must have been put through the door some time in the night.
    He held it carefully. The envelope was poor-quality, official-issue stuff, his name printed on it in blue ink, with 'By hand, Strictly Personal' added underneath and double-underlined. The 'e' in Jericho and in 'Personal' was in the Greek form. His nocturnal correspondent was a classicist, perhaps?
    He took it into the hall to open, Mrs Armstrong at his heels.

    Hut 6
    4.45 A.M.
    Dear Mr Jericho,
    As you expressed such a strong interest in medieval alabaster figurework when we met yesterday, I wondered if you might care to join me at the same place at 8 this morning to view the altar tomb of Lord Grey de Wilton (15th cent, and really very fine)?
    Sincerely,
    H.A.W.

    'Bad news, Mr Jericho?' She couldn't quite suppress the note of hope in her voice.
    But Jericho was already dragging on his overcoat and was halfway out of the door.
    Even after taking the hill at a fast trot he was still five minutes late by the time he passed the granite war memorial. There was no sign of her or anyone else in the graveyard so he tried the door to the church. At first he thought it was locked. It took both hands to turn the rusty iron ring. He put his shoulder to the weathered oak and it shuddered inwards.
    The church inside was cave-like, cold and dark, the shadows pierced by shafts of dusty, slate-blue light, so solid they seemed to have been propped like slabs against the windows. He hadn't been in a church for years and the chilly stink of candle wax and damp and incense brought memories of childhood crawling back. He thought he could make out the shape of a head in one of the pews nearest the altar and began to walk towards it.
    'Miss Wallace?' His voice was hollow and seemed to travel a great distance. But when he came closer he saw it wasn't a head, just a priest's vestment, draped neatly over the back of the pew. He passed on up the nave to the wood-panelled altar. To the left was a stone coffin with an inscription; next to it, the smooth, white effigy of Richard, Lord Grey de Wilton, dead these past five hundred years, reclining in full armour, his head resting on his helmet, his feet on the back of a lion.
    'The armour is especially interesting. But then warfare in the fifteenth century was the highest occupation for a gentleman.'
    He wasn't sure where she'd come from. She was simply there when he turned round, about ten feet behind him.
    'And the face, I think, is also good, if unexceptional. You weren't followed, I trust?'
    'No. I don't think so, no.'
    She took a few steps towards him. With her dead complexion and tapering white fingers she might have been an alabaster effigy herself, climbed down from Lord Grey's tomb.
    'Perhaps you noticed the royal arms above the north door?'
    'How long have you been here?'
    'The arms of Queen Anne, but, intriguingly, still of the Stuart pattern. The arms of Scotland were only added as late as 1707. Now that is rare. About ten minutes. The police were just leaving as I arrived.' She held out her hand. 'May I have my note back, please?'
    When he hesitated she presented her palm to him again, more emphatically this time.
    The note, please, if you'd be so good. I'd prefer to leave no trace. Thank you.' She took it and stowed it away at the bottom of her voluminous carpet bag. Her hands were shaking so much she had trouble fastening the clasp. 'There's no need to whisper, by the way. We're quite alone. Apart from God. And He's supposed to be on our side.'
    He knew it would be wise for him to wait, to let her come to it in her own time, but he couldn't help himself.
    'You've checked it?' he said. 'The call sign?'
    She finally snapped the bag shut. 'Yes. I've checked it.'
    'And is it Army or Luftwaffe?'
    She held up a finger. 'Patience, Mr Jericho. Patience. First there's some information I'd like from you, if you don't mind. We might begin with what made you choose those three letters.'
    'You don't want to know, Miss Wallace. Believe me.'
    She raised her eyes to heaven. 'God preserve me: another one.'
    'I'm sorry?
    'I seem to move in an endless round, Mr Jericho,