In Chap­ter 9 of “The Art Thief,” the nar­ra­tive unfolds after a week­end theft, focus­ing on Anne-Cather­ine’s dai­ly rou­tine as she heads to work and Bre­itwieser’s metic­u­lous research into art while plan­ning his next heist. On week­days, he fre­quents local libraries in Mul­house and Stras­bourg, along with the Uni­ver­si­ty of Basel’s art-his­to­ry col­lec­tion, por­ing over the exten­sive Benez­it Dic­tio­nary of Artists. His research approach involves exam­in­ing artists’ cat­a­logues, trac­ing the prove­nance of stolen art­works, and tak­ing metic­u­lous notes, all while read­ing mate­ri­als in Ger­man, Eng­lish, and French.

Bre­itwieser metic­u­lous­ly orga­nizes stolen pieces in fold­ers, com­bined with ref­er­ence mate­ri­als and his own labeled sketch­es. With sup­port from his grand­par­ents, his per­son­al art library grows over time, sur­pass­ing five hun­dred vol­umes, lead­ing to exten­sive learn­ing in var­i­ous art forms and his­tor­i­cal con­text. His deep dive into the life of the artist Georg Petel, whose work he had recent­ly stolen, reveals Petel’s extra­or­di­nary tal­ent and trag­ic end due to the plague at thir­ty-four.

The thiev­ing cou­ple, now inten­si­fied in their activ­i­ties, exhibits a nat­ur­al instinct for risk-tak­ing. Their heists often reveal a vul­ner­a­bil­i­ty in muse­um secu­ri­ty that they seem to exploit, as many small muse­ums rely heav­i­ly on pub­lic trust and offer min­i­mal pro­tec­tion for their art—electing instead to acquire new works to attract patrons rather than for­ti­fy­ing secu­ri­ty. This presents a stark real­i­ty, as while muse­ums aim to fos­ter inti­ma­cy with art, they often leave them­selves open to those like Bre­itwieser who exploit these gaps.

Their audac­i­ty man­i­fests vivid­ly in an escapade at the Uni­ver­si­ty of Basel muse­um, specif­i­cal­ly tar­get­ing a cel­e­brat­ed paint­ing by Willem van Mieris. Despite a secu­ri­ty cam­era, Bre­itwieser devis­es a plan to steal the art­work. Posi­tion­ing him­self strate­gi­cal­ly, he fol­lows through on the theft, con­ceal­ing the paint­ing in a shop­ping bag car­ried by Anne-Cather­ine. Man­aged to evade detec­tion, their heist goes unno­ticed until they’re long gone, with only a vague video cap­ture of a man turn­ing away. Ulti­mate­ly, this chap­ter reveals the duo’s obses­sive knowl­edge of art, their bold­ness in thiev­ery, and the sys­temic vul­ner­a­bil­i­ties with­in muse­ums they con­tin­ue to exploit.