A possible concise summary is:
Angela, Kevin and Oscar are trying to find out who stole $3,000 from the company. They suspect and question everyone in the office, including Michael, but find no evidence. They finally discover that Angela made a mistake in her books and there was no theft. Kevin and Oscar mock Angela for her error.
Here are the key facts extracted from the text:
1. There is $3,000 missing from the office and three accountants are trying to find out who took it.
2. They suspect Michael, the boss, but they have no proof.
3. They interview everyone in the office, but no one admits to taking the money.
4. They search Michael's office for evidence, but they only find receipts from a joke and magic shop.
5. They discover that the missing money was actually an accounting error made by one of them.
6. They close the case and no one is accused of stealing.