Frequently, Mrs Castle, 74, would hear other night noises: babble from the pubs flanking her four-storey block, formally named Priam House, but known locally as 'the white flats'; or music from a strip club beyond the railway line.
To these familiar sounds last Sunday night were added the death gurgles of her brother, Bill Bryan, 71, gagged and bound on a chair beside her, and the noises of a burglar (or burglars) ripping her flat apart.
Annie Castle died, it is believed, from a heart attack; her brother, from suffocation. Their fate, unlike the murder of James Alexander, 84, battered to death two days later in Hampstead, north London, may have been unplanned. Unlike Wednesday's non-fatal attack on Elizabeth Baylis, a Hanbury (Hereford and Worcester) pensioner, as she knelt at her parents' grave, the Bethnal Green deaths were free of spattered blood. But such comparisons offer little comfort to the elderly.
Annie Castle was 28 when she and her late husband moved, just after the Second World War, to the house she was killed in last week. This section of the Bethnal Green- Hackney border was tough in those days, but the random viciousness is new. Long plagued by criminal gangs, its conflicts nowadays often reek of racial bigotry. Residents tend to be uncommunicative with strangers.
Last week on Cambridge Heath Road, two women, a 72- year-old widow and a 74-year- old divorcee, shuffled northwards, white-knuckled behind shopping trolleys, heading for the post office. 'We always go out in twos, even during the day,' said the widow. 'When we get to the post office, one of us goes in for her pension while the other stands in the doorway to keep a look-out for muggers. You daren't go to the cinema. You're not safe.' Richard O'Loughlin, 84, looked behind him. Every 50 yards along Hackney Road, he turned to survey the pavement. Born locally and living with his blind wife, his first reflexes warn off strangers. 'I used to box at 14 1/2 stone,' he said, bunching a bicep. 'Feel that]'
According to Help The Aged, elderly people are less likely than other age groups to become victims of crime ('It is estimated that the 'young', aged 16-30, are six times more at risk than people over 60.'). But the elderly of Bethnal Green are uncomforted, feeding fears on tabloid stories. 'Did you see in the Sun, where they hung a lady of 78 upside down?' asked the widow. Her companion said: 'There are things in the atmosphere that must be making young people violent.'
They sense a rejection by the young which dehumanises them. Labels such as 'crumblies' and 'wrinklies' and jokes about Zimmer frames are all current, none sympathetic.
Gordon Rae, of Contact, an organisation for relieving loneliness in old age, is appalled by a survey showing that next year only 16 per cent of charitable donations will go to bodies helping the aged, 'despite the fact that the number of people over 75 has doubled in the past four decades'.
Annie Castle habitually left her front door unlocked. 'She trusted people,' said a friend, Dolly Clark. 'She loved you to come in for a cup of her strong tea. We used to call her 'Teabag Annie'.'
Mrs Clark lives in sheltered accommodation off the Cambridge Heath Road. These dwellings are on the site of the old Bethnal Green Hospital where Annie Castle once worked as a cleaner. The first of the 39 elderly residents moved in seven months ago and have no complaints other than that the place has already been burgled three times.
In their common-room last week, some residents spoke of their fear of going out. 'Young rogues could push you over.'
'A lot of elderly people walk about with their worldly possessions in case they're pinched from indoors.'
'It's greed . . . violence on television . . . the way people bring their children up. Children tell their parents what to do. They seem to get everything they want. The whole world has gone pagan.'
George Miskell, 82, born in the hospital, said of Mrs Castle's persecutors: 'They should be tarred and feathered.'
Beside him, Frances Adams, 71, said: 'They should bring back hanging. Our jails are bursting.'
All recalled their own youth, when food was short but neighbour helped neighbour, front- door keys hung from strings inletter-boxes, and fog had more choking power than fingers. They yearned for the days of corporal punishment.
Behind Bethnal Green's sheltered elderly, there is a modern housing estate, imaginatively designed and only a three-minute walk from Priam House. Geraniums and garden gnomes offered assurances of respectability as neighbours Kathy Wymer, 72, and Ivy Hayes, 77, stood at Mrs Wymer's garden gate.
'I worked with Annie in Bethnal Green Hospital years ago,' Mrs Wymer recalled. 'She was a very nice, a special person, who - like me - remembered the bug-eaten days when children were happy around here; when nobody had anything, so nobody would ever break in.
'This is a lovely estate, but if you hung your washing out it would be nicked. There have been two recent break-ins. People blame the coloureds, but it's not them. There are coloureds in that house over there and their children are very well-mannered. I blame them all.'
All the doors on this estate have spy-holes and reinforced locks. A 1991 home safety campaign to provide the elderly with special locks, smoke alarms and front-door chains may have made them feel more threatened. The decision of a local charity to distribute 'personal shriek alarms' is unlikely to quieten their twilight years.