1 INTRODUCTION  
2 STEP SCIENCE GOALS  
2.1 S-PLUS Main Survey Overview and Discovery of Transients in the Southern Hemisphere  
2.2 Supernova Follow Up  
2.3 Gravitational Wave Follow Up During LIGO/Virgo/KAGRA Observing Run 4  
3 STEP PIPELINE OVERVIEW AND DATA ANALYSIS  
3.1 Reduction Processing of T80S and Template Imaging  
3.2 Difference Imaging  
3.3 Transient Candidate Selection  
4 DEEP LEARNING CANDIDATE SELECTION  
4.1 Training, Validation, and Test Data Set  
4.2 Results  
5 EXTRAGALACTIC TRANSIENTS DISCOVERED IN STEP IMAGING  
6 SUPERNOVA FOLLOW-UP  
7 STRATEGY FOR GRAVITATIONAL WAVE FOLLOW-UP DURING LVK O4  
7.1 Gravitational Wave Simulations  
7.2 Kilonovae Sensitivity  
7.3 Candidate Vetting and Analysis  
8 CONCLUSIONS  
8.1 Summary  
8.2 STEP as a GW Follow-up Program  
8.3 The Next STEP in the Rubin Era