The ultimately fruitless search for five-year-old April Jones began as a frantic race against time to find her alive and well.
As the hours turned to days and early optimism evaporated, the focus switched to the bleak reality of recovering her body.
In those early days no one imagined they were involved in the biggest search in British policing history - with a budget to match.
Official estimates have put the bill for searching for the missing schoolgirl at £2.4 million.
Running, as it ultimately did, from October 1 2012 to April 19 2013, the search took in tens of thousands of man hours and a mountain of resources.
From the outset, the search for April was a large-scale operation with dozens of professionals and hundreds of volunteers.
Once all hope of finding her alive receded, the eager though amateur volunteer efforts were no longer appropriate.
Then the meticulous professional task of combing the rugged countryside around Machynlleth began in earnest.
Detectives identified more than 650 individual search areas, taking in more than 23 square miles of terrain.
A total of 150 officers worked together each day, regularly starting at 8am and carrying on until it was too dark to continue.
Dyfed Powys police had 23 members of staff working in the Holmes major incident room at the height of the investigation.
The Home Office Large Major Enquiry System (Holmes) is an IT network used to investigate serial killings and major crimes.
The system carefully sifts a mass of information as it comes in and ensures that vital clues are not overlooked.
It is designed to be completely compatible and consistent across all police forces in England, Scotland, Wales, and Northern Ireland.
In addition to high tech IT, Dyfed Powys received support from more than 45 forces across the UK for searching and investigating.
The search operation eventually concluded on April 19 after running, with very few breaks, for almost seven months.
On average, 16 search teams consisting of six officers and one leader have been out scouring the countryside around Machynlleth every day.
Backing them up have been six police search advisors (POLSA) and a team of 10 highly-trained police dogs.
Up to 100 mountain rescuers have taken part in the operation over its duration, climbing rugged and potentially dangerous terrain.
The Dyfed Powys Police marine unit has led river and sea search efforts, aided by a team of kayakers and two RNLI vessels.
During the inquiry, launched in parallel with the search, police received 4,744 individual calls and messages from the public.
Officers conducting house-to-house inquiries visited 700 properties in and around the west Wales market town.
From the calls, messages and conversations received, 2,159 actions were identified for officers to follow up.
During the investigation, 1,018 written statements were taken and 2,918 exhibits were seized.
Twitter followers of the Dyfed Powys Police feed increased from 2,400 in the last week of last September to more than 12,500 in the first week of October.
Over the same period, visits to the police website rose from 18,455 unique visits to almost 100,000.