← Back to Books

Bill Cosgrove Mysteries · Prequel Short Reads

The Cosgrove Case Files

Six complete cases from the years before The Locked Drawer. Each one is a short read, finished in an evening, and each one turns on a single everyday security idea shown at work rather than explained from a lectern.

  1. 1TriageNov 10, 2026
  2. 2The Fourth StepDec 8, 2026
  3. 3Clear in RetrospectJan 5, 2027
  4. 4SurfdogFeb 2, 2027
  5. 5Tea HourMar 2, 2027
  6. 6The Second DrawerMar 30, 2027

How they work

Start anywhere. Every road leads to the same week.

One complete case

Every Case File opens and closes inside its own pages. Start with any of them.

Made for an evening

Short enough to finish in a sitting, and each one ends on a thread that leads to the next.

Habits worth keeping

Each case turns on one everyday security idea, shown at work rather than explained from a lectern.

Six cases, one road

All six lead to the week that The Locked Drawer begins.

The Case Files

Six cases, in the order Bill worked them.

The system closed the case. Bill didn't.

Triage cover, Cosgrove Case File 1

Case File One ·

Triage

Madison, Wisconsin, autumn 2032. A new tool ranks every case before Detective Bill Cosgrove sees it. It calls one stolen savings account an easy case and another not worth a phone call. It is wrong about both. A complete case, and the one of six.

How a lure is built, and how to read one

A look-alike web address, a code stolen in real time, and a transfer nobody meant to make. Bill takes each apart, and shows what would have stopped it, and how a careful question to an AI assistant finds what a ranking tool misses.

Pre-order on Amazon (opens in a new tab)

Outside the US? Pre-order from Amazon.ca·Amazon.co.uk·Amazon.com.au

Setting
Madison, autumn 2032
The case
Two files, one lure
What it teaches
Reading a phishing lure
ISBN
978-1-997050-09-4

The password was strong. The door was old.

The Fourth Step cover, Cosgrove Case File 2

Case File Two ·

The Fourth Step

Madison, Wisconsin, January 2033. Bill Cosgrove has a license, a one-room office above a used bookstore, a radiator that clanks, and no clients. Then a parish priest sends him the first one: a coffee volunteer whose email has been quietly taken over. A complete case, and the two of six.

How an email account is taken without a single guess

Why the oldest address on an account can matter most, why two-step sign-in goes on the email first, what to tell the people who were tricked in your name, and how to write a careful question for an AI assistant.

Setting
Madison, January 2033
The case
A parish email, taken over
What it teaches
Account recovery and email security
ISBN
978-1-997050-10-0

Six people were in the room.

Clear in Retrospect cover, Cosgrove Case File 3

Case File Three ·

Clear in Retrospect

Madison, Wisconsin, autumn 2033. A home-care aide is accused of draining an elderly woman's account, and the password was on a sticky note under the keyboard. Attorney Una Suarez asks Bill to find out who actually had access. A complete case, and the three of six.

Who is authorized, and who simply has access

Why a password taped to a device is a shared password, how to let a helper in without handing over the keys, and what to do in the first forty-eight hours after an account is drained.

Setting
Madison, autumn 2033
The case
An aide accused
What it teaches
Shared passwords and delegated access
ISBN
978-1-997050-11-7

The model said nothing was wrong.

Surfdog cover, Cosgrove Case File 4

Case File Four ·

Surfdog

November 2034. Ted Park found a pattern that an exchange's fraud model was built not to see, and he showed it to the room anyway. Bill sets down the story the way Ted told it. A complete case, and the four of six.

Why the loss just under the line goes unseen

How an exchange's fraud model works: thresholds, speed rules, and why small losses at volume slip through. And what a customer can set up that the model will not do for them: alerts, withdrawal limits and delays.

Setting
Another coast, late 2034
The case
A pattern in a fraud model
What it teaches
How fraud models and thresholds work
ISBN
978-1-997050-12-4

No one calls about your computer.

Tea Hour cover, Cosgrove Case File 5

Case File Five ·

Tea Hour

Madison, Wisconsin, January 2035. A bridge-group regular lets a helpful 'technician' into her laptop, and her bank calls the transfer authorized. Bill takes the case from the senior center's tea table. A complete case, and the five of six.

Never let a caller drive your device

What remote-access software is and how to tell if it is on your computer, why 'verify the transfer' is the theft itself, and how to push past a bank's first no.

Setting
Madison, January 2035
The case
A call about a virus
What it teaches
Remote-access and tech-support scams
ISBN
978-1-997050-13-1

The number on the screen proved nothing.

The Second Drawer cover, Cosgrove Case File 6

Case File Six ·

The Second Drawer

February 2035. A weekend in Milwaukee becomes a favor: a colleague's mother moved her savings to a 'safe account' on the word of a caller whose number looked like her bank's. Set in the week before The Locked Drawer begins. A complete case, and the six of six.

Why caller ID proves nothing

How a spoofed number and a 'safe account' script work, why a bank never asks you to move money, and the one habit that stops it: hang up and call the number on the back of the card.

Setting
Milwaukee, February 2035
The case
A 'safe account' call
What it teaches
Bank-impersonation and spoofed caller ID
ISBN
978-1-997050-14-8

Where the Case Files lead

The Locked Drawer

The Locked Drawer is the first Bill Cosgrove mystery, arriving April 13, 2027. Every Case File is a prequel to it, and each one plants something a reader will recognize when the novel opens.