A 94-year-old grandmother is seriously ill in hospital with a fractured skull and partially severed finger after being beaten in her own bed as she slept.
Police said Emma Winnall also suffered a broken arm and wrist in the "vicious" and "sickening" assault at her West Midlands home.
Her carer raised the alarm at 9am on Tuesday but detectives said the attack, which left her with potentially life-threatening injuries, could have occurred at any time from 9pm on Monday night.
Mrs Winnall, of Pensby Close, Moseley, in Birmingham, was taken to hospital and remains under sedation after emergency surgery, which involved inserting metal plates into her arm.
Detectives have been unable to determine a motive for the attack. Nothing was stolen from the property and the interior was largely undisturbed.
A photograph of Mrs Winnall in hospital has been released at the request of her daughter as part of a police appeal for information.
Detective Chief Inspector Sarb Johal, of West Midlands Police , said police believe "an implement of some sort" was used in the attack.
Officers said Mrs Winnall is showing signs of improvement in hospital.
DCI Johal continued: "This is a truly sickening attack on a defenceless, frail lady as she slept in her own home.
"Mrs Winnall had nothing of note to steal. It was a senseless assault and I'd urge anyone with suspicions about who may be responsible to get in touch straight away.
"The attacker may well have mentioned something to a friend or relative, or perhaps someone remembers a person acting oddly that evening or the following morning."
Anyone with information is asked to contact West Midlands Police on the 101 number or the independent charity Crimestoppers in confidence on 0800 555 111